Mick Foley first retired in February 2000, after losing a HIAC match to Triple H (even though he wrestled at the following month's WrestleMania 2000 event). He made several subsequent appearances in the WWF, often as a commissioner and frequently having humorous interactions with E&C Dynasty. At the end of 2003, things got serious as Randy Orton contronted him, and eventually he faced Orton and Evolution in a tag match with The Rock at WrestleMania XX, as well as facing Orton in a No Holds Barred match at the next month's Backlash.
Eventually, Mick Foley joined Total Nonstop Action in September 2008 and he won the TNA World Heavyweight Championship from Sting in April 2009 and the TNA Legend's Championship from Kevin Nash in July 2009. He left TNA in June 2011.
He has currently written nine books, including four autobiographies, three books of children's fiction, and two novels of adult fiction.
Outside of wrestling, Mick Foley has made numerous appearances, but mostly with some wrestling tie-in. Prior to WrestleMania 2000, The Rock hosted Saturday Night Live, in which HHH, Big Show, and Foley appeared before the opening monologue where Vince McMahon asked them not to attack Rock during the show. In 2009, Foley voiced Thunder Clap, a "Drunken Fighter" (strongly resembling Hulk Hogan in both appearance and speech), on Squidbillies.