Shirley Phelps-Roper confirmed that Phelps, 84, died Wednesday evening at Midland Care Hospice, the (Topeka) Capitol-Journal reported. Nathan Phelps, an estranged son, said last week that his father was dying but a church spokesman, Steve Drain, denied those reports.
The church has also refused to comment on Nathan Phelps' report that Westboro excommunicated his father last year.
Phelps became pastor of the new Westboro Baptist in 1955 when it was associated with another Topeka church but then broke off the relationship. The church eventually gained a notoriety out of proportion to its size because of pickets inspired by Phelps' virulent views on homosexuality.
The church used the slogan "God hates fags" for its website. While it had conducted pickets in Kansas for several years, it became nationally known in 1998 when church members showed up at the funeral of Matthew Shepard, a gay college student tortured and killed in Wyoming.
Most of the church's members were from Phelps' extended family, although some of this children broke ties with him and accused him of being abusive.
Phelps received a law degree in 1964. He was known for taking civil rights cases and was honored by a local NAACP group in the 1980s.
But he was disbarred in Kansas in 1977 after pursuing a legal vendetta against a court reporter over a delayed transcript. In 1985, he was barred from practicing in the federal courts.
Phelps founded the Phelps Chartered Law Firm, where some of his children, including Phelps-Roper still practice. Their work has included fighting federal and state laws aimed at limiting Westboro's picketing, especially at military funerals.