Adélard Lanctôt (February 13, 1874 – April 17, 1919) was a lawyer and political figure in Quebec. He represented Richelieu in the Canadian House of Commons from 1907 to 1911 as a Liberal.
He was born in St-Philippe de Laprairie, Quebec, the son of Louis Lanctôt and Rosalie Robidoux. Lanctôt was educated in Montreal and at the Université Laval. In 1902, he married Sarah Dery. Lanctôt practised law in Sorel. He was first elected to the House of Commons in an 1907 by-election held after Arthur Aimé Bruneau was named a judge. Lanctôt died in Sorel at the age of 45.