Background and career
Glenn Franklin Howerton III (; born April 13, 1976) is an American actor, comedian, writer, and producer. He is best known for playing Dennis Reynolds on the FX/FXX sitcom It's Always Sunny in Philadelphia (2005–present), which he co-developed and serves as an executive producer and writer alongside the other main cast members. Howerton's other notable performances include Cliff Gilbert on The Mindy Project (2012–2017), Don Chumph on the first season of Fargo (2014), Jack Griffin on A.P. Bio (2018–2021), and Jim Balsillie in the film BlackBerry (2023). He also co-hosted The Always Sunny Podcast (2021–2023) with his fellow It's Always Sunny co-stars and co-creators Rob McElhenney and Charlie Day.
Howerton was born in Okinawa Prefecture, Japan on April 13, 1976, the son of American parents Janice and Glenn Franklin Howerton Jr. He has an older sister named Courtney. His father was a fighter pilot in the United States Armed Forces, and the family frequently moved due to his military career. After Howerton's birth, his family returned to the U.S. to live in Arizona and then New Mexico. When he was three years old, they relocated to United Kingdom, where they lived in Felixstowe. Four years later, they again returned to the U.S. to live in Virginia. They then had a stint in South Korea, where they were based in Seoul. When he was 10 years old, they returned to the U.S. for a third time and settled in Montgomery, Alabama. After graduating from Jefferson Davis High School in Montgomery, Howerton moved to Miami, where he spent two years at the New World School of the Arts of Miami Dade College. In 1996, he entered Juilliard School's Drama Division in New York City, where he graduated with a BFA as part of Group 29 (1996–2000).
In 2002, Howerton starred as Corey Howard in That '80s Show. He went on to guest star on ER as Dr. Nick Cooper in 2003. He had small roles in the films Must Love Dogs (2005), Serenity (2005), Two Weeks (2006), and The Strangers (2008). He also appeared as a doctor in Crank (2006), and reprised the role in its 2009 sequel, Crank: High Voltage. Howerton is best known for playing the narcissistic and sociopathic Dennis Reynolds on the FX sitcom It's Always Sunny in Philadelphia (2005–present). The series was co-created by Howerton alongside Rob McElhenney and Charlie Day, who all serve as producers, writers, and main cast members alongside Kaitlin Olson and Danny DeVito. As of season 14, he has also directed two episodes. In December 2021, It's Always Sunny became the longest-running live-action American comedy of all time with the release of its 15th season. The series is still ongoing as of April 2026, with its 18th season in the works. In 2008, Howerton co-created sci-fi comedy Boldly Going Nowhere with Day, McElhenney, and writing assistant Adam Stein, but the pilot was permanently shelved. He has also had producing roles on various projects created by other It's Always Sunny colleagues, like David Hornsby, such as CBS sitcom How to Be a Gentleman, adult animated sitcom Unsupervised, and Fox sitcomThe Cool Kids. Howerton also did several voice roles, including a recurring part on The Cleveland Show as Ernie Krinklesac. In 2013, he played the lead role in a film for the first time, landing the character of Will in the CollegeHumor comedy film Coffee Town with co-stars Steve Little and Ben Schwartz. Soon after, he landed recurring roles on the Fox comedy series The Mindy Project (2012–2017) as Cliff Gilbert, the divorce lawyer introduced in season two as one of Mindy's love interests, on the critically acclaimed first season of the FX dark comedy series Fargo (2014–present) as Don Chumph, and on the Showtime comedy-drama series House of Lies (2012–2016) starring Don Cheadle in its final season as the young mayoral candidate Seth Buckley. Howerton also played a small part as the gun-running Dominic in the Netflix Original film Officer Downe (2016) starring Kim Coates. His next major television role came in 2018 on the NBC single-camera comedy created by Mike O'Brien, A.P. Bio (2018–2021), where he played Jack Griffin, an arrogant Harvard philosophy professor whose fall from grace forced him to get a job teaching biology to high school students in his hometown of Toledo, while plotting to exact revenge on his nemesis and restore his career. The show ran for two seasons on NBC before it was cancelled and then picked up by Peacock, NBC's streaming service, where it ran for another two seasons. In December 2021, it was cancelled for good. In October 2022, it was announced that he would be voicing Fred Jones on the upcoming HBO Max animated series Velma. Starting in November 2021, Day, McElhenney, and Howerton launched The Always Sunny Podcast, a weekly show loosely based on the rewatch format of podcasting, which had grown in popularity in recent years, to coincide with the release of the record-breaking 15th season of It's Always Sunny. In June 2022, they released Four Walls Whiskey, with all proceeds from the 15-year single-malt Irish whiskey going toward supporting the Pennsylvania hospitality industry, which was badly hit by the pandemic. In August 2022, it was announced that Howerton would be co-starring with Jay Baruchel in a Canadian biopic directed by Matt Johnson on the rise and fall of BlackBerry, portraying one of its co-founders. The film BlackBerry (2023) premiered in competition at Berlinale 2023 on February 17 to positive reviews from critics, with Howerton's performance as Jim Balsillie being especially well received. In 2025, he played Ethan Corbin III on the Netflix dark comedy limited series Sirens. That same year, he also guest starred as his It's Always Sunny character, Dennis Reynolds, in the ABC sitcom Abbott Elementary during a cross-over event.
Howerton dated actress Morena Baccarin while they were both attending Juilliard. He married actress Jill Latiano on September 5, 2009, following an engagement that lasted for over a year. They have two sons together, the first born in 2011 and the second born in 2014. Howerton was diagnosed with ADHD in 2023.
