Roch Lanctôt (January 30, 1866 – May 30, 1929) was a Canadian politician.
Born in Saint-Constant, Canada East, Lanctôt was educated at the University of Ottawa.
A farmer by occupation, he was first elected to the House of Commons of Canada for the electoral district of Laprairie—Napierville in the general elections of 1904.
A Liberal, he was re-elected in 1908, 1911, 1917, 1921, 1925, and 1926.