French soldier and writer who explored parts of what are now Canada and the United States and who prepared valuable accounts of his travels in the New World.

Lahontan went to Canada in 1683 as a marine lieutenant. He participated in an unsuccessful campaign against the Iroquois Indians on Lake Ontario in 1684 and commanded Fort-Saint-Joseph (now Niles, Mich.) in 1687. In 1688–89 he explored territory along the Wisconsin and the Mississippi rivers.

On a return trip to France in 1692 with a plan for a fleet on the Great Lakes, Lahontan, now a captain, stopped at Newfoundland and defended the French colonists at Plaisance against the English. For this action he was made king's lieutenant at Plaisance but when the governor there accused him of insubordination, he fled to Portugal in 1693 and thereafter remained in Europe.

In 1703 Lahontan published Nouveaux voyages de Mr. le Baron de Lahontan dans l'Amérique septentrionale, 2 vol. (New Voyages to North-America), considered the best 17th-century work on New France. The New Voyages also contained a series of dialogues describing the philosophy of the primitive way of life that influenced a subsequent growth of primitivism in France and England, as reflected in the works of Montesquieu (Montesquieu, Charles-Louis de Secondat, baron de La Brède et de), Voltaire, Jonathan Swift (Swift, Jonathan), and others.