Religion Reference Guide, Census of Population, 2021

Skip to text

Text begins

Definitions and concepts

Since 1871, the decennial Census of Population has included a question on religion that reflects a longstanding, continuing and widespread demand for information about religious affiliation and diversity in Canada.

Religion refers to a person’s self-identified connection to or affiliation with any religious denomination, group, body, or other religiously defined community or system of belief. Religion is not limited to formal membership in a religious organization or group.

For infants or children, religion refers to the specific religious group or denomination, if any, in which they are being raised.

When completing the census, a person who has no religious affiliation can choose either to mark the answer circle for “No religion” or to specify other responses, such as “Atheist” (does not believe in the existence of God) or “Agnostic” (believes nothing can be known about the existence of God).

Governments, along with religious groups, denominations and associations across the country, commonly use information on religion. For example, religious leaders and organizations use this information to plan programs and to help determine where to build churches, synagogues, mosques and temples. Data on religion are also used to understand the diversity of the country.

For additional information, please see the Dictionary, Census of Population, 2021, Statistics Canada, Catalogue no. 98-301-X.

Questions

The 2021 Census of Population data on religion were obtained from Question 30 on form 2A-L and form 2A-R. For the 2021 Census, the 2A short-form questionnaire was used to enumerate all usual residents of 75% of private dwellings. The 2A-L long-form questionnaire, which also includes the questions from the 2A short-form questionnaire, was used to enumerate a 25% sample of private households in Canada. For private households in First Nations communities, Métis settlements, Inuit regions and other remote areas, the 2A-R questionnaire was used to enumerate 100% of the population.

Both versions of the questionnaire used the same wording for the religion question: “What is this person’s religion?” Below the question, a note asked respondents to indicate a specific denomination or religion even if the person was not currently a practising member of that group. Both questions included a write-in box, in which respondents could report their denomination or religion. Alternatively, respondents with no religious affiliation could report this information using the mark-in circle labelled “No religion,” located directly below the write-in box.

To help respondents to better understand the question, the 2A-L questionnaire included the following 13 examples of denominations and religions: Roman Catholic, United Church, Anglican, Muslim, Baptist, Hindu, Pentecostal, Lutheran, Presbyterian, Sikh, Buddhist, Jewish and Greek Orthodox. These examples were chosen and ordered based on their response frequency in the 2011 National Household Survey, which replaced the long-form census that year.

Meanwhile, the 2A-R questionnaire included the following examples: Roman Catholic, Anglican, United Church, Traditional (North American Indigenous) Spirituality, Pentecostal, Baptist, Lutheran, Presbyterian, Jehovah’s Witness, Church of Jesus Christ of Latter-day Saints, Longhouse, Moravian and Salvation Army. These examples were chosen and ordered based on the response frequency among Indigenous respondents in the 2011 National Household Survey.

To help respondents to better understand the question and encourage them to provide more detailed responses than in previous censuses, the 2A-L and 2A-R electronic questionnaires also included a link to a list of over 200 additional examples of religions and religious groups or denominations. In the paper versions of the 2A-L and 2A-R questionnaires, a note indicated that respondents should visit Examples of religions and religious groups/denominations to view these additional examples. Examples in the linked list were based on reporting patterns from the 2011 National Household Survey, as well as engagement with stakeholders and experts. A note at the top of the page indicated that these are only examples of different religions and religious groups or denominations and that there may be others that are not on the list. Examples in the list were ordered alphabetically by broad religion, then by major denomination (if applicable) and by more specific denomination (if applicable).

Additional instructions on how to complete the 2021 religion question were available for respondents via a help button accessed through the online questionnaire:

Information on the historical comparability of the 2021 Census religion question with questions asked in the 2011 National Household Survey and in earlier censuses is provided in the sections of this document entitled Concepts over time and Comparability over time.

For more information on the reasons why the census questions are asked, please refer to the five fact sheets found on The road to the 2021 Census web page.

Classifications

The detailed list of religions and religious groups or denominations disseminated for the 2021 Census and their comparability with those disseminated for the 2011 National Household Survey and the 2001 Census are available in Appendix 2.14 of the Dictionary, Census of Population, 2021, Statistics Canada, Catalogue no. 98-301-X. The 2021 Census includes data on more than 200 religions and religious groups or denominations reported by people living in Canada.

Religion is a difficult concept to measure, and there is no internationally recognized classification for this concept. Data users, academic experts and representatives from various religious groups have provided advice to Statistics Canada in developing the list of religions disseminated for the 2021 Census of Population.

Concepts over time

Over time, the census has incorporated differences in the wording, format, examples and instructions for the religion question. These differences have affected the historical comparability of religion data.

Changes to the religion question

The religion question that appeared in the 2021 Census, “What is this person’s religion?” was the same as the one that was asked in the 2011 National Household Survey and in the 2001 and 1991 censuses. It also had the same basic format: there was a write-in box in which respondents could report their religion, as well as a mark-in circle for indicating “No religion.” In contrast, the 1981 and 1971 censuses had mark-in circles with pre-printed names of religions, followed by a mark-in circle for indicating “No religion.”

However, other elements of the question have been revised since the 2011 National Household Survey, despite the wording of the question itself remaining the same for 2021, including the following:

• In 2021, the order of the 13 examples of denominations and religions included on the 2A-L questionnaire was revised in accordance with response frequency in the 2011 National Household Survey. On the 2A-R questionnaire, the order of the examples was also revised in accordance with the response frequency from Indigenous people in 2011. In addition, the example “Salvation Army” replaced “Evangelical Missionary Church.”
• The electronic versions of the 2021 question on religion provided a new link to a page with over 200 different examples of religions and religious groups or denominations. In paper versions of the 2021 question, respondents were instructed to go to a website (Examples of religions and religious groups/denominations) to see these examples.

The results of the 2019 Census Test indicated that, for the main religions (Christianity, Hinduism, Islam, Judaism, etc.), and for the broader Christian denominations (Anglican, Pentecostal, Presbyterian, United Church, etc.), the revised 2021 version produces results that are comparable with the results for the 2011 question.

As indicated, examples of religions and religious groups or denominations continued to be listed directly on the questionnaire. Without these examples, the 2019 Census Test found that, in particular, many members of Christian denominations reported more general responses, such as “Christian.” Therefore, removing these examples would make the data less useful to many users.

However, the link to the list of more than 200 examples of religions and religious groups or denominations encouraged many respondents to provide more specific responses. After reviewing this extensive list of examples, respondents affiliated with non‑Christian religions were more likely to provide a more detailed response (e.g., “Sunni Muslim” rather than “Muslim,” or “Orthodox Jewish” rather than “Jewish”). Similarly, respondents affiliated with a Christian denomination were more likely to provide a more detailed response (e.g., “Anglican Church of Canada” rather than “Anglican”).

The modified content in the 2021 question encouraged respondents to provide more specific responses, so data on a much greater number of religions and denominations have been disseminated (see Changes to the religion variable). However, data users will still be able to produce estimates comparable with 2011 by aggregating the more detailed response categories for a religion or a broad denomination.

Changes to the religion variable

The revised approach for the 2021 Census, along with changing immigration patterns and increasing diversity in Canada, yields more varied and diverse responses to the religion question than the approach used in past censuses. To better reflect the range of responses received, data on a greater number of religions and religious groups or denominations have been disseminated for the 2021 Census.

For the first time, in 2021, the religion variable provides information on over 100 additional religions and religious groups or denominations. As a result, this variable now details over 200 religions. Statistics Canada was guided by the advice of data users, academic experts and representatives from various religious groups when developing the list of religions disseminated for the 2021 Census of Population.

For the detailed list of religions disseminated for the 2021 Census and their comparability with those disseminated for the 2011 National Household Survey and the 2001 Census, please refer to Appendix 2.14 in the Dictionary, Census of Population, 2021, Statistics Canada, Catalogue no. 98-301-X.

Information on the historical comparability of the 2021 Census religion data is provided in the Comparability over time section.

Collection and processing methods

The COVID-19 pandemic emerged in Canada in early 2020 and affected all steps of the 2021 Census process, from data collection to dissemination. Please refer to the Guide to the Census of Population, 2021, Statistics Canada Catalogue no. 98-304-X, for more detailed information on this topic.

Data quality

The 2021 Census of Population underwent a thorough data quality assessment. The different certification activities conducted to evaluate the quality of the 2021 Census data are described in Chapter 9 of the Guide to the Census of Population, 2021, Statistics Canada Catalogue no. 98-304-X.

The data quality assessment was conducted in addition to the regular verifications and quality checks completed at key stages of the census. For example, throughout data collection and processing, the accuracy of specific steps such as data capture and coding was measured, the consistency of the responses provided was checked, and the non-response rates for each question were analyzed. As well, the quality of imputed responses was assessed during data editing and imputation.

During the data quality assessment, a number of data quality indicators were produced and used to evaluate the quality of the data. These indicators are briefly described below. Finally, resulting census counts were compared with other data sources and certified for final release.

The main highlights of this assessment of the data pertaining to Religion are presented below.

Variability due to sampling and total non-response

The objective of the long-form census questionnaire is to produce estimates on various topics for a wide variety of geographies, ranging from very large areas (such as provinces and census metropolitan areas) to very small areas (such as neighbourhoods and municipalities), and for various populations (such as Indigenous peoples and immigrants), that are generally referred to in this document as “populations of interest.” In order to reduce response burden, the long-form census questionnaire is administered to a random sample of households.

This sampling approach and total non-response introduce variability into the estimates that needs to be accounted for. This variability also depends on the population size and the variability of the characteristics being measured. Furthermore, the precision of estimates may vary considerably depending on the domain or geography of interest, in particular because of the variation in response rates. For more information on variability due to sampling and total non-response in long-form census questionnaire estimates, please refer to the Guide to the Census of Population, 2021, Statistics Canada Catalogue no. 98-304-X.

Non-response bias

Non-response bias is a potential source of error for all surveys, including the long-form census questionnaire. Non-response bias arises when the characteristics of those who participate in a survey are different from those who do not.

In general, the risk of non-response bias increases as the response rate declines. For the 2021 long-form census questionnaire, Statistics Canada adapted its collection and estimation procedures to mitigate the effect of non-response bias to the extent possible. For more information on these mitigation strategies, please refer to the Guide to the Census of Population, 2021, Statistics Canada Catalogue no. 98-304-X.

Data quality indicators

A number of quality indicators were produced and analyzed during the 2021 Census of Population data quality assessment. Four indicators are available to data users for long-form content: the total non-response (TNR) rate; the confidence interval; as well as the non-response rate and the imputation rate per question.

The total non-response (TNR) rate is the primary quality indicator that accompanies each disseminated 2021 Census of Population product, and is calculated for each geographic area. It measures total non-response at the dwelling level. Non-response is said to be total when no questionnaire is returned from a dwelling or when a returned questionnaire does not meet the minimum content. More information on the TNR rate is available in Chapter 9 of the Guide to the Census of Population, 2021, Statistics Canada Catalogue no. 98-304-X.

The confidence interval was selected as a variance-based quality indicator to accompany the 2021 Census of Population long-form estimates because it helps users easily make a statistical inference. This indicator provides a measure of the accuracy of the long-form estimates. Using a science-based approach, research and simulations were done to ensure that confidence intervals are constructed using adequate statistical methods for the Census of Population data and areas of interest.

A confidence interval is associated with a confidence level, generally set at 95%. A 95% confidence interval is an interval constructed around the estimate so that, if the process that generated the sample were repeated many times, the value of the interest parameter in the population would be contained in 95% of these intervals. The confidence interval consists of a lower bound and an upper bound. These two bounds accompany the long-form estimates in most data tables.

Further details on the different methods used to construct confidence intervals and their assumptions are provided in the Sampling and Weighting Technical Report, Census of Population, 2021, Statistics Canada Catalogue no. 98-306-X.

The non-response rate per question is a measure of missing information due to non-response to a question. It measures only the non-response that is resolved through imputation during data processing (as opposed to weighting when a sample is used). For the long-form questionnaire, the non-response rate per question includes only partial non-response to the question, except for First Nations communities, Métis settlements, Inuit regions and other remote areas where both partial and total non-response are taken into account. Partial non-response is when answers to certain questions are not provided for a respondent household.

The non-response rate per question for a question on the long-form questionnaire is defined as the sum of the weights of in‑scope units in the population of interest who did not respond to the question divided by the sum of the weights of in‑scope units in the population of interest. Here “units” refers to the statistical units for which data are collected or derived (e.g., persons or households, depending on whether the question is about a person-level characteristic or a household-level characteristic). A unit is considered to be in scope for a given question if the question is applicable to that unit and the unit belongs to the population of interest related to the question.

The imputation rate per question measures the extent to which responses to a given question were imputed. Imputation is used to replace missing data in the event of non-response or when a response is found to be invalid (e.g., multiple answers are provided when a single answer is expected). Imputation is conducted to eliminate data gaps and to reduce bias introduced by non-response. Imputation is generally done by identifying persons or households in the same geographical area with similar characteristics to the incomplete record and copying their values to fill in the missing or invalid responses.

The imputation rate for a question on the long-form questionnaire is defined as the sum of the weights of in-scope units in the population of interest for which the response to the question was imputed divided by the sum of the weights of in-scope units in the population of interest (see the definition of “units” provided in the above section on the non-response rate per question).

For long-form content, imputation for most areas is done to resolve partial non-response—not total non-response, which instead is treated by weighting. However, in First Nations communities, Métis settlements, Inuit regions and other remote areas, whole household imputation (WHI) is used to resolve total non-response. It first imputes the occupancy status of non-respondent dwellings and further imputes all the data for those dwellings resolved as occupied in the first step. WHI is included in the imputation rate per question, including the use of administrative data to impute non-responding households in areas with low response rates; see Appendix 1.7 of the Guide to the Census of Population, 2021, Statistics Canada Catalogue no. 98-304-X. As with the non-response rate, a unit is considered to be in scope if the question is applicable to that unit and the unit belongs to the population of interest related to the question.

The non-response and imputation rates per question can be interpreted as the proportion of in-scope units in the population of interest for which information was not reported or was imputed, respectively. The long-form rates are weighted to reflect the fact that the long-form questionnaire is only distributed to a sample of the population, so in this case, the proportion is estimated.

The non-response and imputation rates for a question are often similar, but some differences can be observed for a given question because of additional data processing steps that may have been required. These rates were regularly checked during data assessment, and a detailed analysis was done if there was a difference between the two rates for a question, to ensure the appropriateness of the processing steps taken and the quality of the data. A difference between the non-response rate and the imputation rate for a question can generally be explained by one of the following two factors:

• Some responses were considered invalid or inconsistent during the edit stage and imputation was needed, which is why the imputation rate is higher than the non-response rate for a question.
• Some non-responses were resolved in a straightforward manner early during data processing because a single resolution was possible based on the answers provided to other questions, making imputation unnecessary. This may explain why the non-response rate is higher than the imputation rate for a question.

Table 1 below presents the non-response and imputation rates per question for Canada and for each province and territory.

The non-response and imputation rates per question at lower levels of geography are also available in 2021 Census data tables presenting data quality indicators. This information is scheduled for release on August 17, 2022, for short-form questions and on November 30, 2022, for long-form questions.

The 2021 Census Data Quality Guidelines, Statistics Canada Catalogue no. 98-26-0006, provides all the information required to understand and interpret the data quality indicators for the 2021 Census, along with guidelines to enable their proper usage. Data quality indicators are provided so that users are informed about the quality of the statistical information and can determine the relevance and the limitations of the data relative to their needs. In general, the quality of the 2021 Census of Population data is very good, but in some cases, data have to be used with caution. It is strongly recommended that users consult all available data quality indicators to get a better sense of the quality of the data products they are interested in.

Certification of final counts

Once data editing and imputation were completed, the data were weighted to ensure that estimates represent the total Canadian population living in private dwellings. Certification of the final weighted estimates was the last step in the validation process, which led to the recommendation to release the data for each level of geography and domain of interest. Based on the analysis of the data quality indicators and the comparison of long-form census questionnaire estimates with other data sources, the recommendation is for unconditional release, conditional release, or non-release (for quality reasons on rare occasions). For conditional release or non-release, appropriate notes and warnings are included in the products and provided to users. Moreover, other data sources were used to evaluate the long-form census questionnaire estimates. However, since the risk of error often increases for lower levels of geography and for smaller populations, and the data sources used to evaluate these counts are less reliable or not available at these lower levels, it can be difficult to certify the counts at these levels.

Long-form census questionnaire estimates are also subject to confidentiality rules that ensure non-disclosure of respondent identity and characteristics. For more information on privacy and confidentiality, please refer to Chapter 1 of the Guide to the Census of Population, 2021, Statistics Canada Catalogue no. 98-304-X. For information on how Statistics Canada balances the protection of confidentiality and the need for disaggregated census data, with specific attention to new 2021 Census content, please refer to Balancing the Protection of Confidentiality with the Needs for Disaggregated Census Data, Census of Population, 2021, Statistics Canada Catalogue no. 98-26-0005.

For more information on data processing and the calculation of estimates and their level of precision, please refer to the Sampling and Weighting Technical Report, Census of Population, 2021, Statistics Canada Catalogue no. 98-306-X.

Data quality for religion

The non-response and imputation rates for the religion question in the 2021 Census are shown in Table 1. At the national level, the non-response rate for the religion question was 1.4% and the imputation rate was 1.8%. Across the provinces, the imputation rate ranged from 1.2% in Prince Edward Island to 3.0% in Saskatchewan. It was higher in the territories, particularly in Nunavut (25.9%). In the territories, as well as in First Nations communities, Métis settlements, Inuit regions and other remote areas in the provinces, the COVID-19 pandemic presented some challenges for conducting the Census of Population, including some that affected in-person enumeration, such as travel restrictions and unavailability of local staff.

Comparability over time

The question on religion has been revised for the 2021 Census. A description of the changes and their impact on historical comparability is included in the section of this document entitled Concepts over time.

Beyond the impact of the changes to the question on religion, other factors can influence changes in responses to this question over time, including the social environment at the time of the census and the importance of religion to the respondent.

This means that two respondents with the same religious affiliation could have different response patterns and thus could be counted as having different religions. For example, a respondent could report “Evangelical Lutheran Church” as their religion, while another respondent with the same religious affiliation could report “Lutheran” or “Christian” instead. Therefore, data on religion can be fluid. Nevertheless, data on religion from the Census of Population reflect respondents’ perception of their religious affiliation at the time of collection.

Comparability with other data sources

The 2021 Census is currently Statistics Canada’s primary source of data on religion. Prior to 2021, this information was collected in the 2011 National Household Survey and in decennial censuses from 1871 to 2001.

In addition, the General Social Survey Program collects data on various components of religion through its annual survey cycle. The information collected includes religious affiliation, religious practice, and the importance of an individual’s religious or spiritual beliefs.

Occasionally, other household surveys (such as the Survey of Safety in Public and Private Spaces) also collect data on religious affiliation.

Many factors affect comparisons of religion data across these sources. Among other factors, comparability is affected by:

• differences in survey target populations, reference periods, sampling and collection methods
• question wording, questionnaire format, examples and instructions
• approaches to data processing
• the social and political climate at the time of data collection.

For additional information, please see the Guide to the Census of Population, 2021, Statistics Canada Catalogue no. 98-304-X.