"AHS" writer-director-producer Murphy declined to elaborate on what character Bomer would play, saying only that the role was "warped."
"AHS: Freak Show" will debut Oct. 8 in the 10 PM ET slot.
According to FX, "'American Horror Story: Freak Show' begins its tale in the quiet, sleepy hamlet of Jupiter, Florida. The year is 1952. A troupe of curiosities has just arrived to town, coinciding with the strange emergence of a dark entity that savagely threatens the lives of townsfolk and freaks alike. This is the story of the performers and their desperate journey of survival amidst the dying world of the American carny experience."
The season will also feature Jessica Lange, Kathy Bates, Sarah Paulson, Patti LaBelle, Frances Conroy, Evan Peters, Denis O'Hare, Gabourey Sidibe, Emma Roberts, Finn Wittrock, Michael Chiklis, John Carroll Lynch and "Hunger Games" actor Wes Bentley.
Watch a teaser below: