The actor, whose death on Monday shocked the world, portrayed a gay man in the 1996 film The Birdcage and cross-dressed in hit comedy Mrs. Doubtfire, roles which led the Topeka-based church to claim Williams made "merchandise of filthy proud sin".
The church posted a series of tweets following the 63-year-old actors' alleged suicide, including "@ABC: @BarackObama on the passing of Robin Williams: "He was one of a kind."more evidence of how very evil he was..." and "We [sic] in Bay Area with "Robin in Hell" signs. Show us the memorial/candlelight vigil service! #havesignwilltravel!"
Members of the church are currently protesting at the Apple, Facebook and Twitter headquarters in their latest God Hates the Media Campaign as Williams' funeral arrangements have yet to be announced by the actor's family.
According to a coroner's report, preliminary findings have revealed that Williams took his own life. He had been suffering from severe depression at the time.
Williams leaves behind three grown children - Zachary, with his first wife Valerie Velardi, and Zelda and Cody with his second wife Marsha Garces.
The church has previously picketed at the funerals Sylvester Stallone's son, Sage, and Jackass star Ryan Dunn. They came under fire for picketing at military funerals with hateful language and offensive gestures.
Numerous Christian groups have denounced the church's actions.
@Rob1nWilliams @RobbyWilliams_ @RobinWilliamsTw @RWFansite Westboro Baptist Church to protest #RobinWilliams funeral: pic.twitter.com/hsGrcp8Ro6
— Westboro Baptist (@WBCSays) August 12, 2014BREAKING: God has required Robin Williams' soul! There can be no doubt - he's in hell's fire! pic.twitter.com/G27U81nx49
â€" Westboro Baptist (@WBCSays) August 11, 2014