The seventeenth season of the American television sitcom series It's Always Sunny in Philadelphia premiered on FXX on July 9 and concluded on August 20, 2025, consisting of eight episodes. Episodes were simulcast on FX and had same night availability on the FXNOW website, and next day availability on Hulu. The season stars Charlie Day, Glenn Howerton, Rob Mac, Kaitlin Olson, and Danny DeVito as "the Gang". In December 2020, after the fourteenth season aired, It's Always Sunny in Philadelphia was renewed for four additional seasons. Filming took place from October to December 2024.
After the fourteenth season aired, It's Always Sunny in Philadelphia was renewed for four additional seasons in December 2020, intending to take it up to season 18. At the 75th Primetime Emmy Awards, series creator and showrunner Rob Mac and Quinta Brunson, the creator and star of the ABC sitcom Abbott Elementary, began developing a crossover between the two series, which was later approved by the Walt Disney Company CEO Bob Iger.
On August 4, 2024, Charlie Day posted on Instagram that the writers' room would start working on the season in the following week. The writing team for the season includes Mac, Day, David Hornsby, Javi Scott, Nina Pedrad, and Keyonna Taylor.
According to star Danny DeVito, filming for the season was expected to begin in September 2024. By October 16, it was announced via Instagram that filming had begun. On December 4, it was announced that filming for the season had finished.
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The season premiered with two episodes on July 9, 2025.
On Rotten Tomatoes, the season has an approval rating of 90% based on 12 reviews. The website's critics' consensus is, "Unlike Paddy's merry band of morons, It's Always Sunny in Philadelphia remains sharp and spry in its advanced age."