Mestre Irineu, or Raimundo Irineu Serra, was the founder of Santo Daime, a spiritual doctrine from Brazil that blends elements of Catholicism, Spiritism, and Indigenous traditions, centered around the ritual use of ayahuasca (called Daime). Born in Maranhão in 1892, he had a visionary experience in the Amazon rainforest that led him to establish the doctrine in the 1930s in the state of Acre. He is regarded by his followers as a spiritual guide and enlightened master with a divine mission.