It’s Always Sunny in Philadelphia Season 18 Cast, Guest Stars and Release Guide

The It’s Always Sunny in Philadelphia Season 18 cast brings the five members of the Gang back to Paddy’s Pub: Rob Mac as Mac, Charlie Day as Charlie Kelly, Glenn Howerton as Dennis Reynolds, Kaitlin Olson as Dee Reynolds and Danny DeVito as Frank Reynolds. FX confirms that the new season contains ten episodes and premieres on FXX on August 17, 2026, with episodes streaming on Hulu the following day.

The first trailer also points to a large group of familiar recurring characters. Carol Kane returns as Sam after Frank chose her in the Season 17 Golden Bachelor parody. Mary Elizabeth Ellis is back as the Waitress, Mary Lynn Rajskub appears as Gail the Snail, Artemis Pebdani returns as Artemis and Andrew Friedman is seen as Uncle Jack. Reports around the season have also teased the McPoyles and another appearance connected to filmmaker Guillermo del Toro.

Season 18 continues the show’s stated return to its roots while sending the Gang into new targets, including workplace automation, conspiracy culture, live-action role-playing, Renaissance fairs and Little League. For other current ensemble comedies, see our Adults Season 2 cast and This Fool Hulu cast.

Rob Mac as Mac

Rob Mac, formerly credited as Rob McElhenney, returns as Ronald “Mac” McDonald. Mac remains the Gang member most likely to turn a passing idea into a rigid identity, whether he is presenting himself as a security expert, athlete, moral authority or master strategist. His confidence usually grows in inverse proportion to his understanding.

Mac is also the creator of It’s Always Sunny and serves as a writer and executive producer. That dual role has made the character central to the show’s willingness to evolve while keeping its basic comic engine intact. Season 18’s stories about role-playing, physical competition and modern workplaces all provide natural settings for Mac’s need to perform competence.

Charlie Day as Charlie Kelly

Charlie Day returns as Charlie Kelly, the illiterate, inventive and frequently filthy co-owner of Paddy’s Pub. Charlie can be the Gang’s most innocent member in one scene and its most alarming problem-solver in the next. His bond with Frank remains one of the series’ strongest pairings, while his obsession with the Waitress continues to produce consequences long after any normal person would have stopped.

Day also writes and executive produces. Ahead of the season, he described the new run as a collection of large episodes and teased returning characters, including the McPoyles, as well as Guillermo del Toro. The specific nature of those appearances should remain unspoiled until FX releases full episode information.

Glenn Howerton as Dennis Reynolds

Glenn Howerton plays Dennis Reynolds, whose vanity, manipulation and belief in his own sophistication regularly turn the Gang’s schemes darker. Dennis often begins as the person insisting on standards, only to reveal that his standards are entirely self-serving. Modern themes such as automation and conspiracy theories offer him fresh ways to imagine that he is controlling a system that is actually exposing him.

Howerton is also a writer and executive producer. His precise delivery and sudden explosions of rage remain essential to the show’s rhythm. A Dennis plot works best when his elaborate self-image is allowed to build before reality punctures it.

Kaitlin Olson as Dee Reynolds

Kaitlin Olson returns as Dee Reynolds, Dennis’s twin sister and the Gang’s favorite target. Dee wants recognition as an actor and comedian, but she is every bit as selfish and reckless as the men who dismiss her. Her attempts to prove superiority often reveal how deeply she has adopted the group’s values.

Olson also leads High Potential, but FX’s Season 18 material continues to present Dee as a full member of the core ensemble. The trailer places her inside the wedding and funeral-style chaos surrounding Frank and Sam, as well as the larger group adventures. Fans of high-pressure restaurant comedy can compare a very different performance style in our The Bear Season 3 Episode 1 review.

Danny DeVito as Frank Reynolds

Danny DeVito plays Frank Reynolds, the wealthy financier of the Gang’s worst ideas and Charlie’s roommate. Frank’s money can solve practical barriers, but his appetites and total lack of shame usually make every plan more extreme. Season 17 ended with Frank choosing Sam, played by Carol Kane, and Season 18 appears to continue that relationship into a wedding storyline.

The trailer suggests the celebration takes a macabre turn, but viewers should not treat every cut as a literal plot summary. Comedy trailers often rearrange shots to create a bigger reveal. What is clear is that DeVito and Kane are paired again and that Frank’s version of romance will not resemble a conventional sitcom wedding.

Carol Kane as Sam

Carol Kane returns as Sam, the woman Frank selected during the Golden Bachelor parody. Her reappearance gives Season 18 direct continuity with the previous finale, something Sunny sometimes avoids in favor of a reset. The new footage shows wedding preparations, Sam with Frank and later imagery that appears funeral-like.

Kane’s offbeat warmth works well against Frank’s feral behavior. Sam can appear strange enough to plausibly choose him without simply becoming another member of the Gang. The question is whether the relationship gives Frank a rare emotional attachment or only creates a new structure for the group to destroy.

Mary Elizabeth Ellis as the Waitress

Mary Elizabeth Ellis returns as the Waitress, the long-suffering woman Charlie has pursued throughout the series. FX lists Ellis among the official cast, and the Season 18 trailer places the Waitress with the women around Sam’s wedding events.

The character has moved far beyond being an anonymous object of Charlie’s affection. Her own instability, anger and poor decisions make her capable of matching the Gang when she chooses. Ellis is also married to Charlie Day in real life, though the fictional relationship remains deliberately dysfunctional.

Mary Lynn Rajskub as Gail the Snail and Artemis Pebdani as Artemis

Mary Lynn Rajskub appears again as Gail the Snail, Dee and Dennis’s cousin whose behavior makes even the Gang uncomfortable. Artemis Pebdani returns as Artemis, Dee’s theatrical friend and one of Frank’s most memorable partners. The trailer groups Gail, Artemis and the Waitress around Sam, creating a combination that promises almost no sensible support for the bride.

Both characters work because they enter the Gang’s world with their own bizarre confidence. They are not normal outsiders reacting in horror; they can escalate a situation independently. Their presence also gives Dee scene partners who do not automatically accept Dennis, Mac and Charlie as the center of every story.

Andrew Friedman as Uncle Jack

Andrew Friedman returns as Jack Kelly, Charlie’s uncle and a lawyer with a fixation on the appearance of his hands. Trailer footage suggests a ventriloquism-related scheme, though FX has not released an official episode synopsis explaining it.

Uncle Jack is most effective in small doses because his anxieties become instantly recognizable. Bringing him into a story about performance, deception or a family gathering can create chaos without needing a long reintroduction.

Will the McPoyles and Guillermo del Toro return?

Charlie Day teased the McPoyles and Guillermo del Toro while discussing the season with Deadline. The McPoyle family has been played by recurring actors including Jimmi Simpson and Nate Mooney, but a complete Season 18 guest list was not published in the official FX synopsis at the time of writing. Del Toro previously appeared as Pappy McPoyle.

The safest expectation is that at least one major episode will bring back that corner of the show’s history. Fans should wait for credits or an official episode description before assuming every family member returns. Sunny frequently uses brief cameos alongside larger guest arcs.

What is Season 18 about?

FX describes ten “setups” that continue the show’s return to its roots. The Gang will confront workplace automation and conspiracy theories, participate in LARPing and Renaissance-fair culture, and become involved with Little League. These are topical settings, but Sunny usually makes the Gang’s selfishness the real target rather than delivering a straightforward message.

Automation can expose how little actual work happens at Paddy’s. Conspiracy culture is a natural fit for characters who accept any theory that benefits them. A Renaissance fair lets Mac and Dennis adopt status fantasies, while Charlie can thrive in a world where normal language and hygiene are already unstable. Little League creates a competitive system the Gang can corrupt while insisting they are helping children.

The show’s longevity depends on keeping that structure flexible. A new social trend enters Paddy’s, each character sees a different opportunity, temporary alliances form, and the plan collapses because none of them can tolerate another person winning. Viewers looking for another long-running comedy ensemble can also read our The Four Seasons Netflix cast guide, though its tone and characters are very different.

Season 18 release schedule

Season 18 premieres Monday, August 17, 2026, on FXX. Hulu adds episodes the next day in the United States. FX confirms a ten-episode season, an increase from several recent eight-episode runs.

Individual episode titles and a complete weekly calendar were not included in the official page available for this guide. Unless FX announces a multi-episode launch, the standard expectation is one new FXX episode per week followed by next-day Hulu streaming. That expectation should be updated once the network publishes its detailed listings.

For readers following another FX comedy on Hulu, our The Bear Season 5 ending explained is available after viewing that separate series.