Robert Lanctôt (born November 19, 1963) is a former Canadian politician and lawyer.
A lawyer by profession, Lanctôt was elected as a member of Parliament (MP) for the Bloc Québécois in the 2000 federal election representing the riding of Châteauguay.
On December 11, 2003, following Paul Martin's election as leader of the governing Liberal Party of Canada and the day before Martin's swearing in as Prime Minister, Lanctôt crossed the floor to join the Liberals.
His defection occurred days after his riding association passed a resolution stating it no longer wished to work with the MP and did not want him to run for the BQ in the next election.
[1] Lanctôt ran as a Liberal in Châteauguay—Saint-Constant in the 2004 federal election but was defeated by the BQ's Denise Poirier-Rivard.