James M. "Jim" Foster (November 19, 1934 – October 31, 1990) was an American LGBT rights and Democratic activist. Foster became active in the early gay rights movement when he moved to San Francisco following his undesirable discharge from the United States Army in 1959 for being homosexual. Foster co-founded the Society for Individual Rights (SIR), an early homophile organization, in 1964. Dianne Feinstein credits SIR and the gay vote with generating her margin of victory in her election to the San Francisco Board of Supervisors in 1969.