Mariano Gagnon OFM, born Joseph Theodore Gagnon (October 7, 1929 – April 28, 2017) was an American Franciscan friar and Catholic priest, who served as a missionary in Peru. Gagnon founded the Cutivereni mission in Peru's Ene River valley to assist the indigenous Asháninka people who were being forced out of their homes in the jungle by settlers. He would later become known for his work helping arm the Asháninka and eventually helping some Asháninka flee Cutivereni when it was facing attack from Shining Path guerrillas during the Internal conflict in Peru. He later wrote about his experiences during the conflict in the book "Warriors in Eden".