The first season of It's Always Sunny in Philadelphia, premiered on FX on August 4, 2005. The season contains 7 episodes and concluded airing on September 15, 2005.
The guys hire Dee's friend, Terrell to promote the bar. Meanwhile, Charlie tries to prove that he is not a racist.
A girl from Charlie's past reveals they have a child together. Mac sees the benefits in being a pro-life advocate, while Dennis uses an abortion rally to meet women.
After reminiscing about high school, the guys conclude that it would be a public service if they allowed teens to drink in the bar, thus providing a safe and controlled environment for teens to party. Feeling that she missed out on a lot as a teenager due to having to wear a brace for her scoliosis, Dee begins dating a high school jock.
After discovering that he might have cancer, Mac and Dennis attempt to find a woman who will sleep with Charlie. In the midst of their search, Mac falls in love with a transsexual he meets at the bar named Carmen. Overwhelmed by the extra workload that she had to take on since Charlie has taken a leave of absence, Dee tries to get Dennis to hire a recently out of work actress friend to help out.
The guys buy a gun after the bar's safe is stolen.
Mac and Dennis befriend a patron found dead at their bar in order to win the affection of his granddaughter.