Léon Gérin (French pronunciation: [le.ɔ̃.ʒe.ʁɛ̃]; May 17, 1863 – January 15, 1951) was a Canadian lawyer, civil servant, and sociologist. Born in Quebec City, Canada East, the son of Antoine Gérin-Lajoie, Gérin studied at the Séminaire de Nicolet before receiving a law degree from Université Laval in 1884. In 1886, he went to Paris for a few months and became interested in sociology. Returning to Canada, he settled in Ottawa and worked for the federal government and the House of Commons of Canada.