The third season of It's Always Sunny in Philadelphia aired in the fall of 2007 on FX. It ran for 15 episodes. It is available for purchase on DVD or iTunes.
The Gang's narcissism spins out of control, as usual. First they scheme to do good: adopting a dumpster baby, volunteering with environmental activists, and trying to make the city safer through vigilantism. Then they scheme to become famous: attempting to make a viral video as news reporters and club hoppers, as well as to try out for the Philadelphia Eagles.
The Gang's jealousy and greed make their usual appearance. The Gang fights over Barbara's inheritance, after she wills her house to Dennis. Dee gets jealous of her high school friend and starts a sweatshop, while the entire gang struggles to compete with a local bar and then attempts to sell the bar to a corporate chain.
The Gang is suspected of various crimes: Dennis, Dee and Frank assume that Mac is a serial killer, while Dennis is accused of being a registered sex offender. Meanwhile, the gang inadvertently sells some cocaine it found on the cheap, forcing them to turn to crime and prostitution to earn the money back before the Mob whacks them.
Finally, the Gang struggles to save themselves from Charlie's mistakes. First, the McPoyles get revenge on the Gang for revealing their false molestation charge last season, taking the entire gang hostage. Then Charlie's illiteracy strikes again, and the Gang schemes against its enemies and themselves to save the bar from being given away as a dance contest prize. Also, Mac is gay.
- Glenn Howerton as Dennis Reynolds
- Kaitlin Olson as Deandra Reynolds
- Rob McElhenney as Mac
- Charlie Day as Charlie Kelly
- Danny DeVito as Frank Reynolds
- Mary Elizabeth Ellis as The Waitress
- Lynne Stewart as Bonnie Kelly
- Sandy Martin as Mrs. Mac
- Artemis Pebdani as Artemis
- Jimmi Simpson as Liam McPoyle
- Nate Mooney as Ryan McPoyle
- Thesy Surface as Margaret McPoyle
- Brittany Daniel as Carmen
- Gregory Cummins as Luther Mac
- David Hornsby as Rickety Cricket
- This season has 15 episodes, 5 more than Season 2 and more than twice as many as Season 1. As Seasons 4 through 7 all have 13 episodes, this makes Season 3 the largest season of episodes in the history of It's Always Sunny in Philadelphia.
- This is the first season with a two-part episode: The Gang Gets Whacked (Part 1) and The Gang Gets Whacked (Part 2).