In a one-minute video he posted earlier in the week, he announced he's changing his name to ... Rob Mac. It'll be "mostly" a stage name, and, er, Mac explained that lots of people have had trouble pronouncing it or spelling it over the years.

Kaitlin Olson says her kids are "really not happy" about their dad Rob McElhenney changing his name. The 'It's Always Sunny in Philadelphia' actor filed to legally change his name on June 26.

Rob McElhenney’s new last name has high potential. But for his wife and “It’s Always Sunny in Philadelphia” co-star, Kaitlin Olson, she isn’t fazed by the switch-up from McElhenney to “Mac.” The actor filed to legally change his name last week and is waiting for the court to make it official.