Din Yero Thomas (/ˈdiːn/; born September 28, 1976) is an American former mixed martial artist who was featured on The Ultimate Fighter 4: The Comeback. In the Ultimate Fighting Championship, Thomas is a UFC 41 Lightweight Tournament Semifinalist. He holds a Black belt in Brazilian Jiu-Jitsu under Ricardo Liborio and currently runs two successful Brazilian Jiu-Jitsu and MMA academies in Port St. Lucie, Florida.[2] Thomas holds notable victories of (UFC Lightweight Champion) Jens Pulver, (UFC Welterweight Champion) Matt Serra, and (Strikeforce Lightweight Champion) Clay Guida.

Thomas has acted in local independent films, portraying The Fight Kid in Chris Fuller's Loren Cass and Reverend Pierce in Natalie, Queen of Scots.[3] He appeared alongside Dana White and former opponent Matt Serra on Dana White: Lookin' for a Fight,[4] and currently is a cast member of the UFC Live Weigh-in Show.