Father Sean is a Roman Catholic priest who ministers at St. Jerome's Catholic School.
He was the priest who was educating Bart Simpson in the Catholic Church. Bart was sent to St. Jerome's after being falsely expelled by Principal Skinner who blamed Groundskeeper Willie's prank on him from Springfield Elementary. On his first day of school at Saint Jerome's, Bart is penalized by a nun and told to hold up two dictionaries, in order to feel some of the pain Jesus Christ felt during his crucifixion. After finding Bart in the hallway, Father Sean regaled Bart with the tale of how he converted to Catholicism after a drunken fight with his father. After the fight, badly injured and lying against a lamp post, St. Peter appeared to Sean and told him to mend his rebellious ways. Father Sean gave Bart a comic book of the various saints in order to get Bart interested in the Roman Catholic faith. At home, Bart begins to show to his family his new found religious beliefs, which worries Marge. Homer, at Marge's request, goes to the school to talk to Father Sean. Upon seeing the pancake dinner/bingo night, Homer also becomes infatuated with the Catholic Church, and asks to celebrate the Sacrament of Confession.
After realizing that he could not receive absolution without being a Catholic, both Homer and Bart decide to convert. Meanwhile, Marge (worried she might be alone in Protestant Heaven while Bart and Homer are in Catholic Heaven) seeks help from Rev. Lovejoy and Ned Flanders, who agree to get them back. While they are learning about First Communion, Marge, Rev. Lovejoy, and Ned capture Bart and bring him to a festival for The Western Branch of American Reform Presbylutheranism. At the festival, Bart is told to listen to the band Quiet Riot (renamed to Pious Riot after their conversion) and play paintball, but never says he wishes to leave the Catholic Church. Homer and Fr. Sean arrive with a motorcycle, shoot Marge's hair with some paintball bullets and engage in a Mexican standoff with Ned and Lovejoy. Bart says it is stupid that all the different forms of Christianity are feuding when the main beliefs are the same. The two groups agree to both fight monogamous gays and stem cells and to take Bart's idea to heart. He also openly criticizes Buddhism.
- Episode – "The Father, the Son and the Holy Guest Star"
- Book – The Book of Moe
- Video game – The Simpsons: Tapped Out