Jean Nicot, sieur de de Villemain (born 1530 in Nîmes, died 1600 ij Paris) was a French nobleman, and diplomat. He was the French ambassador in Lisbon, from 1559 to 1561. He also negotiated the marriage of princess Margaret of Valois, who was five years old at the time, with prince Sebastian of Portugal, who was six years old at the time.