Gagnier is a surname. Notable people with the surname include:
Charles Gagnier (born 1985), Canadian freeskier Claire Gagnier (1924–2022), Canadian soprano Ed Gagnier (baseball) (1882–1946), French-American baseball player Ed Gagnier (gymnast) (born 1936), American gymnast and coach Ève Gagnier (1930–1984), actress and singer in Quebec Gérald Gagnier (1926–1961), Canadian bandmaster, composer, and trumpeter Holly Gagnier (born 1962), American actress J.-J. Gagnier (1885–1949), Canadian musician and music educator John Gagnier (1670?–1740). French orientalist Joseph Gagnier (1854–1919), Canadian clarinetist Laurent Gagnier (born 1979), French footballer Pierre Gagnier, Quebec politician Regenia Gagnier (born 1953), scholar of Victorian and modern British literature René Gagnier (1892–1951), Canadian musician Vincent Gagnier (born 1993), Canadian professional freestyle skier
See also Garnier (disambiguation) Gaynier (disambiguation)