Stewart Gilligan "Stewie" Griffin is a fictional character in the animated series Family Guy.

He is the youngest child of Peter and Lois Griffin. In addition to siblings Chris and Meg, Stewie has a half-brother Bertram who is unknown to the other Griffins.

He is a smart, clever baby with an English accent and he is considered to be the show's breakout character.

He is one year old and has a sophisticated attitude. He reached his first birthday in the season 1 episode "Chitty Chitty Death Bang", and has remained the same age ever since.

He is hell-bent on world domination and matricide, his first target being his mother Lois. Brian and Stewie are love/hate friends throughout the show. His closest friend however is his ambiguously gay teddy bear, Rupert. Stewie himself has exhibited some bisexual tendencies, but has thus far only been involved romantically with females. His hobbies include reading, inventing, and plotting.

His nature and mannerisms are juxtaposed with typical childlike interests and actions. While highly literate and able to cite pop culture references that date much further back than his age would let on, he is also entranced by Raffi and the Teletubbies.

Wizard magazine rated him the 95th greatest villain of all time.