Fred Waldron Phelps, Sr. (born November 13, 1929) is the highly controversial leader of the Westboro Baptist Church, based out of his home in Topeka, Kansas. Phelps is best known for preaching that God hates homosexuals and will punish both them and "fag enablers" (which his church defines as anyone whom they find to be insufficiently anti-gay). He claims events such as the September 11 attacks and Hurricane Katrina are caused by God because of this hatred. He and his followers frequently picket various events, especially gay pride gatherings and funerals of gay men, feeling it is their sacred duty to share their views with others.

Phelps is a self-described "fire and brimstone" preacher who believes that homosexuality and its acceptance have doomed most of the world to eternal damnation. His group is estimated to number between 100-200 members (90 of whom are related to Phelps through blood or marriage). The group is built around an anti-homosexual core theology, with many of their activities stemming from the mantra "God hates fags," which is also the name of the group's webpage. Gay rights activists, as well as Christians of virtually every denomination, have denounced him as a producer of anti-gay propaganda and violence-inspiring hate speech.

Phelps rose to national prominence in 1998 when he and congregants from Westboro picketed the funeral of gay murder victim Matthew Shepard, delivering an obscenity-laden sermon (with focus given to graphic descriptions of homosexual sex acts) informing the mourners that Shepard had gone to hell and that everyone in attendance would join him there. Ever since, Phelps and Westboro have remained in the national limelight for their regular pickets of events ranging from gay pride parades to the funerals of soldiers killed in the Iraq War to grand openings of Starbucks.