Statistics Canada says there are now more millennials than baby boomers in the country, ending the 65-year reign of the post-Second World War generation as the largest cohort in the population.
The federal agency noted the change in its newly released population estimate for July 1, 2023, broken down by age and gender.
The baby boomer generation became the largest in Canada in 1958 — seven years before the last baby boomer was even born. They accounted for 40 per cent of the population from the mid-1960s to the early 1970s.
Many countries are grappling with the reality of an aging population as baby boomers retire. These changing demographics are expected to affect health care needs and governments' tax bases.
Here in Canada, the Liberal government has pitched higher immigration as part of the solution to problems created by aging demographics.
Statistics Canada's report, released on Wednesday, shows federal policies are already having an impact as higher immigration through both permanent and temporary streams in 2022 and 2023 helped slow population aging.
"However, the effect of receiving a high number of immigrants in 2022 and 2023 on the decline of the average and median ages is temporary, as population aging is unavoidable," the report says.
The average age in Canada — 41.6 — dropped slightly, by a tenth of a percentage point, between July 1, 2022 and July 1, 2023. It was the first decline since 1958.
Meanwhile, the number and proportion of people aged 65 years and older have continued to rise.
The federal agency says the share of millennials and generation Z is increasing, while the reverse is true for baby boomers and generation X.
Those trends have helped widen the share of the working-age population, which increased in 2023 after steadily declining over the previous 15 years.
"This change may benefit Canadian society by increasing the size of the working-age population, possibly helping to alleviate the pressures of sectoral labour shortages," the report says.
"However, the high number of new working age Canadians may also put pressure on the delivery of services to the population, housing, transportation and infrastructure."
Statistics Canada estimates generation Z could overtake millennials in numbers sometime between 2038 and 2053.