François Leguat (1637/1639 – September 1735) was a French explorer and naturalist.
Leguat was a French Huguenot originating from the Province of Bresse, now part of the department of Ain, who fled to Holland in 1689 after the revocation of the Edict of Nantes in 1685. Marquis Henri du Quesne had published a book giving a glowing description of the island of Réunion and, with the cooperation of the Dutch East India Company, was planning to establish a colony of French Protestant refugees on the island. Two ships were charted for the purpose and many refugees, including Leguat, were eager to become colonists, but when du Quesne learnt that France had sent a squadron of ships to the island, he abandoned this plan as he wanted to avoid any confrontation with the French. Instead he fitted out a small frigate, L'Hirondelle and instructed the captain, Anthony Valleau, to reconnoitre the Mascarene islands, and to take possession of whatever island was found unoccupied and suitable for colonisation. It appears that the colonists were not informed of this change of plan. On 10 July 1690 Leguat and nine male volunteers boarded L'Hirondelle in Amsterdam, intending to start a new life on the island of Réunion, which they believed had been abandoned by the French. Instead, on 16 May 1691, Leguat and seven companions were marooned on the uninhabited island of Rodrigues.
After spending a year on the island the group became homesick and set about constructing a wooden boat to allow them to escape to the island of Mauritius, then under Dutch control. The first attempt failed when they struck Rodrigues' reef; one of the party subsequently died from some illness (possibly brought about by contact with some poisonous reef fauna). They finally left Rodrigues on 21 May 1693 and spent a week being carried by the prevailing wind and current in their open boat to Mauritius, a distance of 300 nautical miles (560 km).