<P> Seth MacFarlane voices four of the show's main characters: Peter Griffin, Brian Griffin, Stewie Griffin, and Glenn Quagmire . MacFarlane chose to voice these characters himself, believing it would be easier to portray the voices he had already envisioned than for someone else to attempt it . MacFarlane drew inspiration for the voice of Peter from a security guard he overheard talking while attending the Rhode Island School of Design . Stewie's voice was based on the voice of English actor Rex Harrison, especially his performance in the 1964 musical drama film My Fair Lady . MacFarlane uses his own voice while portraying Brian . </P> <P> MacFarlane also provides the voices for various other recurring and one - time only characters, most prominently those of news anchor Tom Tucker, Lois' father Carter Pewterschmidt and Dr. Hartman . He is the only voice to be in every episode . </P> <P> Alex Borstein voices Lois Griffin, Asian correspondent Tricia Takanawa, Loretta Brown and Lois' mother Barbara Pewterschmidt . Borstein was asked to provide a voice for the pilot while she was working on MADtv . She had not met MacFarlane or seen any of his artwork and said it was "really sight unseen". At the time, Borstein performed in a stage show in Los Angeles, in which she played a redhead mother whose voice she had based on one of her cousins . The voice was originally slower (and deeper for the original series), but when MacFarlane heard it, he replied "Make it a little less fucking annoying...and speed it up, or every episode will last four hours ." </P> <P> Mila Kunis is the voice of the character named Meg Griffin . Kunis won the role after auditions and a slight rewrite of the character, in part due to her performance on That' 70s Show . MacFarlane called Kunis back after her first audition, instructing her to speak slower, and then told her to come back another time and enunciate more . Once she claimed that she had it under control, MacFarlane hired her . Kunis described her character as "the scapegoat". She further explained, "Meg gets picked on a lot . But it's funny . It's like the middle child . She is constantly in the state of being an awkward 14 - year - old, when you're kind of going through puberty and what - not . She's just in a perpetual mode of humiliation . And it's fun ." </P>

Who does the voice of loretta on family guy