Studied at Montreal College. McGill University; Doctor of Medicine, Master in Surgery, 1878. Doctor of Medicine; Master in Surgery.
Doctor of Laws.
Degree from McGill University in 1878. He was an attending physician and President of the Medical Board at the Hotel Dieu Hospital in Montreal. He was also a Professor of Clinical Medicine at the location of Laval University then in Montreal.
He was elected to the Legislative Assembly of Quebec for the electoral district of Montréal division northern
6 in an 1895 by-election. A Liberal, he was re-elected in 1897 and 1900.
He was a Minister without Portfolio in the cabinet of Félix-Gabriel Marchand and Simon-Napoléon Parent. He was defeated in 1904.
From 1910 to 1912, he was mayor of Montreal.
He was elected to the Canadian House of Commons for the electoral district of Saint Ann in the 1925 federal election. A Liberal, he was re-elected in the 1926 election. He was defeated in the 1930 election.
The township municipality of Guérin, Quebec was named after him.
In 1901 he was appointed a member of the Council of Public Instruction of the Province of Quebec.
Spouse 1883, Mary (daughter 1886),daughter of Honourable James O’Brien, Senator.