He attended the BFA Music Theatre Program at Elon University for two years before taking a role in West Side Story.
He has been open about being "gay-bashed" in high school, despite being heterosexual.
His first name is actually Thomas; Grant is his middle name. His parents are Tom Gustin and Tina Haney. He has a sister named Gracie and a brother named Tyler. He got engaged to LA Thoma in April of 2017 and they wed in December 2018.
He co-starred with Jane Lynch on the television series Glee.