Antonio de Montesinos or Antonio Montesino (c. 1475 - June 27, 1540) was a Spanish Dominican friar who was a missionary on the island of Hispaniola (now the Dominican Republic and Haiti). With the backing of Friar Pedro de Córdoba and his Dominican community at Santo Domingo, Montesinos was the first European to publicly denounce the enslavement and harsh treatment of the indigenous peoples of the island. His censure initiated an enduring struggle to reform the Spanish conduct towards all indigenous people in the New World. Montesinos' outspoken criticism influenced Bartolomé de las Casas to head the humane treatment of Indians movement.