The 40-year-old Colombian beauty will lend her voice to Peter Griffin's fantasy love interest in an upcoming episode, Entertainment Weekly reported.
While daydreaming, Griffin imagines himself as a telenovela star with Vergara voicing his voluptuous lover.
Later in the episode, Vergara lends her voice to another character, a woman selling roses in a restaurant where Quagmire is trying to convince Griffin to do him a big favor.
Vergara will also appear on a hip hop-themed episode of "The Cleveland Show" on October 7, where she'll play Tia Sofia, a character who tries to talk Cleveland into throwing a quinceaNera for Cleveland Jr's 15th birthday.
Kanye West, Nicki Minaj, Bruno Mars, will.I.Am and ?uestlove also make cameos.
"Family Guy"s star-studded 11th season kicks off September 30 and features appearances by Johnny Depp, Ryan Reynolds, Elizabeth Banks and Kellan Lutz.