Raimundo Irineu Serra, aka Mestre (Master) Irineu, (December 15, 1892 São Vicente Ferrer, Maranhão, Brazil — July 6, 1971), was the founder of a syncretic religion known as Santo Daime.
He later moved to the state of Acre where he worked on rubber plantations. In the city of Brasiléia, which is close to the border of Bolivia, he was in contact with other people from his home state of Maranhão as well as Bolivians, from whom he learned the use of ayahuasca. In these early experiences he encountered the Virgin Mary (the Queen of the Forest) and began receiving the guidance which developed into a religious doctrine throughout the remainder of his long life.