He was born in
Grondines, Quebec to Dr. Joseph-Nérée Gouin, a doctor and Séraphine Fugère and was educated at Sorel College, Lévis College and
Laval University in Montreal. He was called to the
Bar in 1884. He practised with people heavily involved in Canadian and Quebec politics:
Honoré Mercier, whose daughter he married,
Louis-Olivier Taillon,
Raymond Préfontaine,
Joseph-Émery Robidoux, Louis-Philippe Bérard and
Rodolphe Lemieux. He represented major railway companies. He was President of the Quebec Bar in 1910 and 1911. On May 24, 1888, he married Éliza Mercier, daughter of Honoré Mercier. Their son,
Paul Gouin, later led the
Action libérale nationale party. He began his long political career by losing as a
Liberal candidate in the riding of
Richelieu in the
1891 federal election. His first electoral success came in
1897 when he was elected MNA for
Montréal No. 2. He was re-elected in
1900 and
1904. He held the positions of Commissioner of Public Works (1900-1901), then Minister of Colonization and Public Works (1901-1905) in the cabinet of
Simon-Napoléon Parent. Along with his colleagues
Alexander Weir and
Adélard Turgeon, he resigned with a view to overthrowing Parent, who had to leave in the face of this rebellion in his own party. He was appointed
Premier of Quebec on 23 March 1905, a position he held until his resignation in 1920, while also holding the position of Attorney General (1905-1919) and, briefly, Minister of Colonization, Mines and Fisheries in 1907. In the
1908 election, faced with a surge of
nationalists led by
Henri Bourassa and
Armand Lavergne, he ran in both
Portneuf and
Saint-Hyacinthe, as the law of the day allowed. He was elected in the first constituency and defeated by Bourassa in the second. Re-elected in both Portneuf and
Saint-Jean in
1912, he chose Portneuf and was re-elected there in
1916 and
1919. He was responsible for the Workmen's Compensation Act, passed in 1909, the incorporation of
Ungava into Quebec in 1912 and the Good Roads Act. He created the Ministère de la Voirie in 1912. He reorganised municipal administration in
Montreal and developed education by creating normal schools for girls and technical schools in Montreal and Quebec City. He was also responsible for the
École des hautes études commerciales in Montreal, the École centrale de préparation et d'arpentage and the École forestières opened in 1907 at
Université Laval. In 1920, he was appointed to the
Legislative Council as the representative for the Salaberry division. He resigned the following year to run successfully as a Liberal candidate in the federal riding of
Laurier—Outremont in the
general election.
William Lyon Mackenzie King's Liberals then took power and Gouin was appointed
Minister of Justice (1921-1924). He did not stand for re-election in
1925 and returned to the practice of law while sitting on the boards of directors of numerous companies. He was appointed
Lieutenant-Governor on 10 January 1929. On the following 18 March, while in Parliament to prorogue a session that was running late, he suffered a heart attack and died in his office. His death caused a stir. Lomer Gouin is interred in the
Notre Dame des Neiges Cemetery in Montreal. ==Elections as party leader==