Louis-Amable Jetté was born on January 15, 1836, in L’Assomption, Quebec.

He was a Canadian lawyer, politician, judge, professor, and the 8th Lieutenant Governor of Quebec. After classical studies at the Collège de L’Assomption (1842-1853), he attended the law school at the Collège Sainte-Marie. He was called to the bar in 1857 and practised in Montreal. He contributed articles to various Montreal newspapers, e.g., L’Union nationale and L’Ordre. In 1871, he co-founded the Parti National, and in the 1872 federal election, despite his political inexperience, Jetté defeated Sir George-Étienne Cartier and was elected to the House of Commons of Canada representing the riding of Montreal East. He was re-elected in 1874 as a Liberal. In 1878, at the end of his term as an MP, he left politics to become a judge of the Superior Court for the district of Montreal and he joined the faculty of law at the new branch of the Université Laval in Montreal, where he held the chair in civil law. He served as dean from 1890 to 1898. Jetté was named 8th Lieutenant Governor of Quebec in 1898 and retained this office until 1908. He was knighted as a Knight Commander of the Order of St. Michael and St. George (KCMG). Mount Jetté in British Columbia is named for him. Jetté was a member of the Canadian Boundary Tribunal leading to the resolution of the Alaska Boundary Dispute.

In 1862, he married Berthilde Laflamme (1841–1919). He died on May 5, 1920, in Quebec City, Quebec, and is buried in Notre-Dame-des-Neiges cemetery, Montreal.