Robert Dale "Rob" McElhenney (/ˈmækɨl.hɛni/; born April 14, 1977 in Philadelphia) is an American actor. He is best known for his role as Mac on the FX series It's Always Sunny in Philadelphia. He is also credited as creator, developer, and executive producer of the show, which has also provided him with writing and directing credits on various episodes.
- Law & Order (1997) as Joey Timon (episode: "Thrill")
- ER (2004) as Andy Fesh (episode: "Where There's Smoke")
- It's Always Sunny in Philadelphia (2005 - ) as Ronald "Mac" McDonald
- Lost (2007, 2010) as Aldo
- The Mindy Project (2014-2017) as Louis "Lou" Tookers
- Fargo (2017) as Officer Oscar Hunt (episode: "The Law of Non-Contradiction")
- Game of Thrones (2019) as Ironborn soldier (cameo, episode: "Winterfell")
- Mythic Quest: Raven's Banquet (2020 - ) as Ian Grimm
- Actor-Shared Background: Much like Mac, he grew up in an Irish Catholic family in South Philadelphia.
- Celebrity Resemblance: He's noted to bear an uncanny resemblance to Haley Joel Osment, to the point where one of the earliest versions of It's Always Sunny in Philadelphia featured him playing what was supposed to be an older, washed up version of him. It came full circle during the promotion for the series' eight season, which portrayed Osment as having ostensibly taken over for Rob in the part of Mac.
- Dyeing for Your Art: He gained 50 pounds to play 'Fat Mac' in Season 7 of It's Always Sunny in Philadelphia, to prove a point about sitcoms where the characters don't change appearance or get 'worse' as they age. He also got ripped and learned to dance in Season 13.
- Has Two Mommies: Was partly raised by two gay mothers in a domestic partnership.
- Romance on the Set: He's married to his Always Sunny co-star Kaitlin Olson.