The phrase 'that's what she said' dates back decades, appearing in films like Wayne's World, but it became a cultural phenomenon through Michael Scott, played by Steve Carell, in the American version of The Office, which ran from 2005 to 2013. Michael used the line constantly to undercut serious moments, and fans turned it into one of the show's defining running gags. It spread across memes, GIFs, reaction images and soundboards, and remains shorthand for pointing out an accidental innuendo.