"Replaceable You" is the fourth episode of the twenty-third season of the American animated television series The Simpsons. It originally aired on the Fox network in the United States on November 6, 2011. In the episode, Homer gets a new assistant named Roz who is secretly out to steal his job. Meanwhile, Bart teams up with Martin Prince for the upcoming Springfield Elementary science fair, constructing robot baby seals that become popular with the senior citizens at the Springfield Retirement Castle. The role of Roz was played by American actress Jane Lynch. "Replaceable You" was seen by approximately eight million viewers during its original broadcast, and it has received mixed reviews from critics.

The twenty-third season of the American animated television series The Simpsons began airing on Fox on September 25, 2011, and ended May 20, 2012. The showrunner for the season was Al Jean, with three episodes ran with Matt Selman, one of those he also wrote himself. The show's 500th episode, "At Long Last Leave", aired February 19, 2012.