The fifteenth season of the American television sitcom series It's Always Sunny in Philadelphia premiered on FXX on December 1 and concluded on December 22, 2021. This season had next day availability on FX on Hulu and FXNOW. The season consists of eight episodes and makes the series the longest-running live-action scripted comedy series in American television history, surpassing The Adventures of Ozzie and Harriet.[1]
The series was renewed for a fifteenth season in May 2020, making it the longest-running live-action comedy series in American television history, replacing The Adventures of Ozzie and Harriet, which ran for 14 seasons between 1952 and 1966.[2] On April 9, 2020, Rob McElhenney announced that writing had begun for season 15.[3] Filming for the season began in May 2021 and wrapped that October.[4][5] Despite teases that the Ireland arc was shot in Dublin, Ireland, in August and September 2021,[6] the final four episodes of the season were instead shot at Bodega Bay, California due to COVID-19 restrictions in Ireland.[7][8]
The season is the first not to be distributed by 20th Television and instead is distributed by Disney-ABC Domestic Television due to the Disney-FOX merger in December 2017.
On Rotten Tomatoes, the season has an approval rating of 100% with an average score of 9 out of 10 based on 7 reviews, the highest rating since season 11.[13]