Trivia

He is the only cast member of "It's Always Sunny In Philadelphia" who is from Philadelphia.

Although his character in ''It's Always Sunny In Philadelphia'' is very homophobic, Rob was raised by a lesbian couple who have a Domestic partnership.

Worked as a waiter before his acting career took off and even kept it during the first season of ''It's Always Sunny In Philadelphia (2005)''.

In June 2011, the New York Daily News reported that Rob McElhenney had gained 50 pounds in the previous 6 months specifically so that he and the other writers for It's Always Sunny in Philadelphia (2005) would be able to start making "fat jokes" about his character, Mac--particularly ones capitalizing on the pun, "Big Mac". A gain (or loss) of 50 pounds in 6 months represents a very rapid and potentially unhealthy rate of weight change.

Rob and his wife, Kaitlin Olson, had their first child, a son named Axel McElhenney (b. September 1, 2010).

Engaged to Kaitlin Olson as of December 2007.

He was signed on to write and direct a feature film adaptation of the Minecraft video game, with 'Steve Carell' attached for the lead role, but the project was quietly canceled.

2020 became co chairman of Wrexham AFC with Ryan Reynolds.

Rob and his wife, Kaitlin Olson, had their second son, Leo McElhenney (b. April 5, 2012).

In 2021, with Ryan Reynolds, Rob invested over £2,000,000 into Wrexham Association Football Club (Wrexham A.F.C.), and they are Director's at the club with active involvement. Wrexham A.F.C. was formed in 1864 and are the third oldest professional football club in the world.

He is of Irish, German, English, and Scottish descent.

Former roommate of Christopher Backus.

Went to high school with musician Donald McCloskey.

Born on exactly the same date as Sarah Michelle Gellar.

Dropped out of directing A Minecraft Movie (2025).