Donnie Fatso

"Donnie Fatso"
The Simpsons episode
Promotional image for the episode
Episode no.	Season 22 Episode 9
Directed by	Ralph Sosa
Written by	Chris Cluess
Production code	MABF19
Original air date	January 2, 2011 (2011-01-02)
Guest appearances
Jon Hamm as the FBI Agent Joe Mantegna as Fat Tony and Fit Tony
Episode features
Chalkboard gag	"Candy canes are not elf bones"
Couch gag	The Simpsons on the couch is depicted as an Advent Calendar.
Episode chronology
← Previous "The Fight Before Christmas" Next → "Moms I'd Like to Forget"
The Simpsons season 22
List of episodes

"Donnie Fatso" is the ninth episode in the twenty-second season of the American animated television series The Simpsons. It first aired on the Fox network in the United States on January 2, 2011. The plot revolves around an FBI agent, who helps Homer go undercover to infiltrate Fat Tony's mob. Homer agrees to help the FBI in order to reduce his prison sentence on a bribery conviction. This episode is a reference to Goodfellas as well as real-life FBI agent Donnie Brasco.

"Donnie Fatso" was written by Chris Cluess and directed by Ralph Sosa. Critics were polarized with the episode, with criticism stemming from its main plot and cultural references.

Upon its initial airing, the episode received 7.32 million viewers and attained a 3.2/8 rating in the 18-49 demographic, according to Nielsen ratings. "Donnie Fatso" featured guest appearances from Jon Hamm and Joe Mantegna.