A fatsuit, also known as a fat suit or a fat-suit, is a bodysuit-like undergarment used to thicken the appearance of an actress or actor of light to medium build into an overweight or obese character, in conjunction with prosthetic makeup. Fatsuits worn by characters are either deliberately visible or mainly concealed. Most are intended as unseen body padding beneath a costume, others appear as realistic flesh and are viewed directly. A fatsuit is often used to provide comedic effect, as in music videos for "Fat" by "Weird Al" Yankovic, "Marblehead Johnson" by The Bluetones, "Keine Lust" by Rammstein and "Way 2 Sexy" by Drake, and the episode "The Cooper Extraction" of The Big Bang Theory.

Pamela Marie Hupp is an American murderer serving a life sentence in Missouri's Chillicothe Correctional Center for the 2016 shooting of Louis Gumpenberger in her home in O'Fallon, Missouri. Hupp's claim that she had shot Gumpenberger in self-defense after he pursued her into her home wielding a knife was not accepted by law enforcement. She ultimately entered an Alford plea before charges of first-degree murder and armed criminal action could go to trial.