Kira Kosarin is the actress and singer best known for playing Phoebe Thunderman on Nickelodeon’s “The Thundermans,” a role she has now carried across a hit show, a reunion film, and a 2025 spin-off series. Born October 7, 1997, she built her career from a child performer in Florida into an executive producer with creative control over the franchise that made her famous. Her story runs through a Broadway household, a teenage move to Los Angeles, a music career built largely outside the traditional label system, and a marriage to musician Max Chester in 2024.
Quick Facts
- Full Name: Kira Nicole Kosarin
- Date of Birth: October 7, 1997
- Birthplace: New Jersey; raised in Boca Raton, Florida
- Occupation: Actress, singer, producer, director
- Years Active: 2012 to present
- Known For: Phoebe Thunderman in “The Thundermans”
- Spouse: Max Chester (married July 17, 2024)
- Education: Pine Crest School; Brighton Hall School, Burbank, California
- Heritage: Ashkenazi Jewish, with ancestors from Eastern Europe
- Record Label: Republic Records (signed 2022)
- Notable Awards: Kids’ Choice Award, Favorite Female TV Star (Kids), 2025
Who Is Kira Kosarin
Kira Nicole Kosarin is an American actress and singer, born in New Jersey and raised largely in Boca Raton, Florida. She grew up in a household built around performing, since her mother worked as a Broadway actress and her father spent his career as a music director, conductor, and record producer. That combination of acting and music training in the home shows up directly in the two-track career she built as an adult, split between television and songwriting.
Her family’s Ashkenazi Jewish heritage, with roots in Eastern Europe, is something she has spoken about openly on her own social media over the years. As a child she trained in ballet at Boca Ballet Theatre and did gymnastics before acting became her focus. She attended Pine Crest School in Florida for middle school, then later attended Brighton Hall School in Burbank, California, a school that many working child actors attend once their filming schedules pick up.
Early Life and the Move to Los Angeles
Kosarin’s path into acting started with an “acting on camera” workshop that convinced her to pursue television seriously. In 2011, at 13 years old, she and her family relocated to Los Angeles so she could audition full time. Her television debut came the following year, in a 2012 episode of the Disney Channel sitcom “Shake It Up,” where she played a supporting character named Raina Kumar.
That single episode led to bigger opportunities within a year. Nickelodeon was casting a new superhero family comedy, and the role of Phoebe Thunderman would become the part that defined the next decade of Kosarin’s public life.
Breaking Through as Phoebe Thunderman
In 2013, Kosarin was cast as Phoebe Thunderman in “The Thundermans,” a Nickelodeon comedy about a family of superheroes trying to live an ordinary suburban life. She starred opposite Jack Griffo, who played her twin brother Max, and the show ran for four seasons before ending in 2018. Phoebe’s arc, a straight-A student who dreams of becoming a full-fledged superhero while her twin leans toward villainy, gave Kosarin a comedic lead role at an age when most actors are still fighting for guest spots.
The show turned her into a recognizable name among Nickelodeon’s young audience almost immediately. She earned Kids’ Choice Award nominations for Favorite TV Actress in 2015, 2016, and 2017, and again in 2018, though the individual award went to other nominees each time. Her cast still took home the Favorite TV Show award for “The Thundermans” during that run, and she got her first personal Kids’ Choice win years later, in 2025, for the franchise’s spin-off series.
While “The Thundermans” was airing, Kosarin picked up other credits around it. She appeared in a 2015 Nickelodeon television film called “One Crazy Cruise,” playing Ellie Bauer, and made guest appearances on shows including “The Haunted Hathaways,” “School of Rock,” “Henry Danger,” and the game show format “Paradise Run.” That pace of work, a lead role paired with side projects, became a pattern she kept up through her twenties.
Life After The Thundermans Ended
When “The Thundermans” wrapped in 2018, Kosarin was 20 years old and had spent nearly a third of her life playing the same character. In a personal essay written for TODAY.com in 2024, she described being 14 when she was first offered the part and feeling an immediate connection to Phoebe, calling the casting a dream come true at the time. That same essay covers the harder part of the story: the adjustment of growing up in front of an audience and then figuring out who she was once the show ended.
Rather than chasing another multi-camera lead right away, Kosarin shifted her attention toward music and content creation for several years. She kept acting in smaller roles during this period, including a voice part in the 2019 animated Nickelodeon film “Lucky,” a recurring role as Nadia in the second season of the Hulu series “Light as a Feather,” and a part in the 2021 comedy “Supercool” playing Ava. But her main creative energy through the late 2010s and early 2020s went into songwriting and her growing YouTube channel.
Building a Music Career Outside the Label System
Kosarin’s music career largely started independent of a record label, which is unusual for an actress with her level of name recognition. She released her debut single, “Spy,” in March 2018, followed by “Vinyl” in January 2019, then “Love Me Like You Hate Me,” “47 Hours,” and “Take This Outside” that same year. Her debut album, “Off Brand,” came out independently on April 10, 2019.
A planned United Kingdom tour to support the album was announced for summer 2019 but was later cancelled due to scheduling conflicts, with Kosarin promising refunds and new dates on social media at the time. She kept releasing music through the next few years, including the single “Simple” with DJ Carneyval in November 2019 and an independent EP called “Songbird” in July 2020. In March 2022, she signed with Republic Records and released “Mood Ring” as her first single under a major label. Alongside her official releases, she has run a YouTube channel for years where she posts covers and original songs, which helped her build an audience that carried over from her Nickelodeon fan base into music.
Returning to Phoebe Thunderman
Kosarin’s biggest career turn in recent years has been going back to the role that started it all, on her own terms this time. Nickelodeon announced “The Thundermans Return” in March 2023, a reunion film bringing back the original cast, with Kosarin also serving as executive producer. According to her TODAY.com essay, she was initially hesitant about the reunion and pushed for changes to make sure the project stayed true to the original series and brought back the entire main cast rather than a scaled-down version. The film premiered in March 2024.
The reunion’s success led to a full spin-off series, “The Thundermans: Undercover,” announced in May 2024 and premiering in 2025 on Nickelodeon and Paramount+. Kosarin reprised Phoebe as the lead again, continued as executive producer, and also stepped behind the camera to direct an episode titled “Prank You, Next.” That mix of acting and directing on the same show marks a clear shift from her role on the original series, where she was simply the star. Her work on the spin-off earned her a Kids’ Choice Award for Favorite Female TV Star (Kids) in 2025, her first individual win after four earlier nominations. A follow-up film, “Clash of the Thundermans,” was greenlit for 2026, with Kosarin again set to executive produce.
Other Acting Roles and Stage Work
Outside the Thundermans franchise, Kosarin has kept building a broader résumé. In August 2024, she took on the role of Betsy Kelso in three episodes of Netflix’s “That ’90s Show,” a spin-off of the long-running “That ’70s Show.” The role put her in front of a streaming audience distinct from her Nickelodeon fan base, and it came out around the same time she was preparing for the Thundermans spin-off series.
She has also stepped onto the stage. Reporting on her career notes a Broadway appearance in “Beautiful: The Carole King Musical,” where she played songwriter Cynthia Weil, and a run playing Princess Jasmine in the stage musical “Aladdin and His Winter Wish” at Laguna Playhouse in California. Both credits reflect the musical theater background she grew up around, given her mother’s own career on Broadway.
Personal Life and Marriage to Max Chester
Kosarin has been in a relationship with musician Max Chester since 2020. The couple married on July 17, 2024, which Kosarin announced through her own Instagram account. She has generally kept the details of her relationship private, sharing updates on her own terms rather than through tabloid coverage, which fits the broader pattern of how she has managed her public image since leaving the original Thundermans cast as a teenager.
Kira Kosarin’s Influence and What Comes Next
Kosarin’s career stands out for how much control she has taken over her own material as she has gotten older. Going from a cast member on someone else’s Nickelodeon show to an executive producer and episode director on that same franchise’s spin-off is not a common trajectory for a former child star. Her willingness to say no to the first version of the Thundermans reunion, as she described in her own essay, and to push for a version that kept the full original cast, shaped a project that then became successful enough to spawn both a series and another film.
With roughly 40 million followers across her social platforms according to her own official biography, Kosarin has also built a direct relationship with her audience that does not depend entirely on a single show or label. Between “Clash of the Thundermans” heading into production for a 2026 release, her ongoing music releases, and her expanding producing and directing credits, her career is currently moving in more directions at once than at any earlier point since “The Thundermans” first premiered in 2013.
