In the
2021 Census of Population conducted by
Statistics Canada, Tyendinaga had a population of living in of its total private dwellings, a change of from its 2016 population of . With a land area of , it had a population density of in 2021. Mother tongue (2021 census): • English as first language: 96.0% • French as first language: 0.9% • English and French as first language: 0.6% • Other as first language: 1.9% == Industry ==