In the
2021 Census of Population conducted by
Statistics Canada, Amherst 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.
Population trend: Private dwellings occupied by usual residents: 876 (total dwellings: 1613) Mother tongue: • English as first language: 4.9% • French as first language: 92.5% • English and French as first language: 1.4% • Other as first language: 1.4% ==Education==