Louis-Michel Viger (French pronunciation: [lwi miʃɛl viʒe]; September 28, 1785 – May 27, 1855) was a lawyer, banker, businessman, seigneur and political figure in Lower Canada, and then in Canada East in the Province of Canada.

Viger was born in 1785 in Montreal, in the old Province of Quebec. His parents were Louis Viger and Marie-Agnès Papineau, who were part of a rising professional middle class. Their families were also heavily involved in the political life of the province of Lower Canada, created in 1791.

Louis-Michel's grandfather had been a shoemaker, but his four sons all advanced in the social scale. Louis-Michel's father, Louis, began as a blacksmith but eventually became an ironmaster. One of Louis-Michel's uncles, Denis Viger, began as a carpenter but developed a business selling potash to English markets. Another uncle, Joseph Viger, became a lumber merchant, while another uncle, Jacques Viger, was an artisan. All three uncles were elected to the Legislative Assembly of Lower Canada.

Louis-Michel's mother, Marie-Agnès Papineau, was the sister of Joseph Papineau, who began as a surveyor and then became a notary. Joseph Papineau also became a member of the Legislative Assembly.

Several of Louis-Michel's cousins became prominent in the political life of Lower Canada. Louis-Joseph Papineau, son of Joseph Papineau, became the leader of the Parti canadien (later called the Parti patriote) and the Speaker of the Legislative Assembly. He was the most significant leader in the struggles with the appointed governor of the province, and in the Lower Canada Rebellion of 1837–1838. Denis-Benjamin Papineau, brother of Louis-Joseph, was also involved in provincial politics, and became joint premier of the new Province of Canada. Another of Louis-Michel's cousins, Denis-Benjamin Viger, son of Denis Viger, was heavily involved with the Parti patriote and also became joint premier of the Province of Canada, while another cousin, Jacques Viger fils, was the first mayor of Montreal. A cousin on his mother's side, Côme-Séraphin Cherrier, also became a lawyer and was active in the Patriote movement.

Louis-Michel Viger studied at the Collège Saint-Raphaël in Montreal, gaining a classical education. He was a student at the same time as his cousin, Louis-Joseph Papineau. The two cousins formed a life-long friendship. After his studies at Collège Saint-Raphaël, Viger articled in law with his cousin, Denis-Benjamin Viger.

Louis-Michel Viger was admitted to the bar in 1807 and set up practice in Montreal. He quickly gained a reputation as a brilliant and popular young lawyer known for his diligence and competence, as well as his kindness. He developed a large practice, eventually entering into partnership with his cousin Côme-Séraphin Cherrier. His family connections gave him the entrée to many social settings in Montreal, and he acquired the nickname, Le beau Viger. He also began to invest in real estate, and by 1825 his properties in the old town of Montreal were bringing in between £100 and £200 annually.

In 1824, he married Marie-Ermine Turgeon. They would have four children. Marie-Ermine was the daughter of Louis Turgeon, seigneur of Beaumont, who was a member of the Legislative Council of Lower Canada, and had formerly been a member of the Legislative Assembly, supporting the Parti canadien. Louis Turgeon's brother, and Marie-Ermine's uncle, was Pierre-Flavien Turgeon, future Archbishop of Quebec.