Born in Quebec, Canada, La Verendrye later fought in the War of Spanish Succession (1699-1713). He went to Europe where he fought at the battle of Malplaquet (1708) and was badly wounded.

After returning to Canada he became a fur trader and farmer. His brother was given the fur trade rights to a vast area of land north of Lake Superior in 1726, and Pierre joined him in this business.

Pierre decided to search for a route across Canada (believing that Canada was much smaller than it actually is). After talking to Native Americans in what is now Thunder Bay, Ontario, he thought he might be able to reach the Pacific Ocean via the Saskatchewan River.

In 1730, the government of Quebec funded La Verendrye's proposed expedition across Canada. He left Montreal on June 8, 1731, with three of his sons and others. They built forts at Rainy Lake and at Lake of the Woods, and eventually reached Lake Winnipeg, but there were fights with the Sioux Indians in 1736, in which many members of the expedition died, including one of La Verendrye's sons (Jean Baptiste).

La Verendrye continued to search for the Saskatchewan River and the Mandan Indians, who were thought to live on the Saskatchewan River and perhaps know a route to the Pacific Ocean. From Lake Winnipeg, he and his two other sons (Louis Joseph and François) traveled southwest in 1738, where the Mandans lived (on the Missouri River though, not the Saskatchewan River as La Verendrye thought). They returned to the fort at Lake of the Woods in 1739.

La Verendrye returned to Quebec in 1744. He died on December 5, 1749 while planning another expedition in search of the Saskatchewan River. His sons continued to explore Canada.