Thomas was born in Brooklyn, New York, but moved to Los Angeles, California, and now resides there. At age 10 he made his Broadway debut in 2003 as Young Simba in the Broadway production of The Lion King (1994). In 2004, he appeared as Jackie Thibodeaux in the original Broadway cast of Tony Kushner's "Caroline, or Change." He also toured with the company during its five-month run in Los Angeles and San Francisco. Thomas also performed in the Broadway production of the musical version of Alice Walker's The Color Purple (1985). In 2007, he appeared alongside Robin Williams and Terrence Howard in the film August Rush (2007) as Arthur, in which he performed the song "La Bamba," and he was the singing voice of Tyrone in The Backyardigans (2004). Thomas has also guest-starred on Jack's Big Music Show (2005) and Just Jordan (2007). He also appeared as Harper in the iCarly (2007) episode "iCarly Saves TV" and was featured on The Naked Brothers Band (2007) Christmas special. He is a main character on Victorious (2010), in the role of André, which premiered on Nickelodeon on March 27, 2010.