I have given a researcher links to census tables that provide population figures by age group down to the CD and CSD level back to 1991, and CANSIM tables that provide data at the provincial level back to 1971, but I wondered if there was any compilation at the lower levels of geography prior to 1991, or even provincial data prior to 1971 without having to laboriously transcribe it from the printed census volumes
For provincial/territorial population estimates by age and sex before 1971, this information is not publicly accessible on Cansim but we can provide an Excel data file on demand.There are however 3 important differences between those estimates and subsequent estimates. As stated in the note tab, population estimates are as of June 1 (rather than as of July 1), they are not adjusted for census net undercoverage and non-permanent residents are not included in the population estimates. More generally, user should also be aware of differences between Statistics Canada's census counts and population estimates.
For subprovincial areas such as CDs, it is more complicated because of boundary changes that may prevent historical comparisons. However, you could still refer the user to some Cansim tables. First, CANSIM table 051-0030 provides total population estimates for CDs and CMAs as of July 1, 1976 to 1986, according to the SCG 1981. Second, Cansim table 051-0036 provides population estimates by age and sex for CDs and CMAs as of July 1, 1986 to 2007, according to the SGC 2001. Users must be aware that from one SGC to another, borders may shift and geographical units may not be comparable.