Louis Claude de Saint-Martin, French mystic and philosopher (d. 1803)
Louis Claude de Saint-Martin (18 January 1743 – 14 October 1803) was a French philosopher, known as le philosophe inconnu, the name under which his works were published; he was an influential of the mystic and human mind evolution and became the inspiration for the founding of the Martinist Order.

Léonce de Saint-Martin, composer and organist, was a distant relative of Louis-Claude de Saint-Martin.