R. Guy Erwin (born 1958, Pawhuska, Oklahoma) (Osage) is an American Lutheran bishop. He was elected in 2013 to a six-year term as bishop of the Southwest California Synod of the Evangelical Lutheran Church in America (ELCA). Since August 2020, he has served as president of the United Lutheran Seminary in Philadelphia. A member of the Osage Nation, Erwin is the first Native American bishop elected to office in the ELCA. He was ordained as a minister in 2011, two years after the denomination dropped its ban against LGBT clergy. He is the first openly gay bishop in the ELCA.