Tartaglia joined Sesame Street'spuppetry team in a part-time capacity at the age of 16, making him one of the youngest Sesame Street puppeteers in the show's history. He performed as a right hand and many minor characters, including Phoebe, and was the understudy for Kevin Clash's Elmo. He performed as Ernie for the second season of Play with Me Sesame and as Oscar the Grouch for Sesame Street 4D. Tartaglia was also a digital puppeteer for the "Elmo's World" segments and performed the character Tingo on Sesame English. He became a full-time part of Sesame Street at the age of 18.[3]
In 2003, Tartaglia performed as DJ 2 in Animal Jam. He created and puppeteered the roles of Princeton and Rod in the Tony Award-winning BroadwaymusicalAvenue Q, which opened on July 31, 2003.[4] He was nominated for the Tony Award for Best Actor in a Musicalin2004 and left the cast on January 30, 2005.[5][6] Tartaglia reprised these roles in the Las Vegas production of Avenue Q from August to December 2005. He then appeared in Newsical 2006: The Next Edition in December 2005.[7]
In 2006, Tartaglia joined the cast of Beauty and the Beast as Lumière until June 2007. He created, executive produced, and starred in the Playhouse Disney short series Johnny and the Sprites, which expanded to a full 30-minute series on January 13, 2007.[5][8][9] In 2007, Tartaglia provided the voice for Mr. Bluelight in Kmart commercials.[10]
Tartaglia played Pinocchio, Puss in Boots, and the Magic Mirror, and puppeteered the dragon in Shrek The Musical.[5][11] The show opened on Broadway on December 14, 2008. Tartaglia performed until August 16, 2009, returned on December 14, 2009, and stayed until the production closed on January 3, 2010.
Tartaglia played Genie in the production of AladdinatThe Muny in St. Louis from July 5–13, 2012.[16] In 2011, he was named a "Givenik Ambassador" by the Broadway/charity site Givenik. Tartaglia hosted a radio show on Sirius XM On Broadway called Sunday Funday with John Tartaglia.[17] In 2016, he created the PBS Kids series Splash and Bubbles, voicing Splash and other recurring characters.[18] In 2017, he performed Hank in the Netflix series Julie's Greenroom.[19]
In January 2024, it was announced that Tartaglia had joined The Jim Henson Company's development team as creative supervisor of future Fraggle Rock projects, in addition to contributing to the development and production of new television and live show projects for the company.[20]
Tartaglia is gay. Regarding the matter, he has stated "I'm less worried about being a positive role model as a gay person than making sure there are no negative stereotypes of any sort."
He considers "nothing more addictive than the sound of an audience laughing" and, regarding the possibility of being "pigeonholed" as a children's entertainer, stated, "If I get pigeonholed, I get pigeonholed. When I do my dark, one-hour miniseries on Lifetime, you'll know!"[21]
