Born in Terrebonne, Canada East, he was a stockbroker and then founded his own brokerage firm, L. J.

His nephew Rodolphe Forget joined his company and became one of the most important businessmen in the Province of Quebec and an elected member of the House of Commons of Canada.

Louis-Joseph Forget was appointed to the Senate of Canada representing the senatorial division of Sorel, Quebec in 1896.

His great-niece is Thérèse Forget Casgrain, a feminist, reformer, politician and senator.

He died in Nice, France in 1911 and is buried in the Notre Dame des Neiges Cemetery.