Rob McElhenney est né le 14 avril 1977 à Philadelphie,en Pennsylvanie, aux États-Unis. C’est un acteur américain surtout connu pour son rôle de Mac dans la série télévisée Philadelphia. Rob McElhenney est d’ailleurs aussi créateur et producteur exécutif de la série.

Biographie

Before the first season of It's Always Sunny in Philadelphia went into production McElhenney hired actress Kaitlin Olson to play the role of Dee Reynolds. McElhenney became romantically interested in Olson by "around season 2" of the series, believing her to be the funniest woman working in all of show business. McElhenney and Olson later began dating before getting married in California on September 27, 2008.

In 2009, the couple announced their purchase of Skinner's Bar at 226 Market Street in Philadelphia (39°57′00″N 75°08′41″W / 39.949895°N 75.144795°W / 39.949895; -75.144795). It was renamed Mac's Tavern. They had their first child, Axel Lee McElhenney, on September 1, 2010. Olson went into labor at a Philadelphia Phillies game. The couple's second son, Leo Grey McElhenney, was born on April 5, 2012.

In preparation for the seventh season of It's Always Sunny in Philadelphia, McElhenney put on 50 lbs of extra weight and let his beard grow out to give extra humor to his character and add a new comedic direction for the season. His co-star Charlie Day described the weight gain as "disgusting" and that the rest of the cast were "a little on the fence about it for his own personal health and safety". McElhenney subsequently lost 23 lbs in a month after the season was finished filming. He lost more later in the year to film the next season.