Daniel DeWayne Severn (born June 8, 1958) is an American mixed martial artist and professional wrestler, notable for his success in the early years of Ultimate Fighting Championship tournaments. Severn has fought and wrestled for many other mixed martial arts and professional wrestling promotions, including King of the Cage, PRIDE, Cage Rage, WEC, Gladiator Challenge, and the World Wrestling Federation.

Severn was the first world-class wrestler to enter the UFC, foreshadowing the period of dominance by wrestlers such as Don Frye in UFC 8 and 9 and Mark Coleman in UFC 10 and 11. Severn entered the UFC in 1994 at UFC 4: Revenge of the Warriors, where he captured the hearts of many UFC fans by executing two impressive back suplays on Anthony Macias. In the finals of UFC 4, Severn was defeated by Royce Gracie who secured a triangle choke for the victory. The submission loss came after Severn was in Gracie's guard for almost 15 minutes, with the wrestler unable to finish his opponent for lack of striking and submission experience. He soon roared back into mixed martial arts competition, dominating his opponents to capture the tournament championship at UFC 5: Return of the Beast.

Severn went on to win Ultimate Ultimate 1995, a tournament consisting of UFC champions and runners up. Here Severn defeated Paul Varelans, David "Tank" Abbott, and Oleg Taktarov in a single night. He was also victorious over Ken Shamrock at UFC 9 to become the UFC Superfight Champion, his third title win for the promotion.

Severn managed his friend and fellow UFC champion Don Frye during UFC 8. In 1999, Severn founded a new mixed martial arts promotion intended to provide a platform for amateur fighters, called The Danger Zone, in which Severn has also fought. Severn has also trained and became a mentor to notable mixed martial artists including UFC light-heavyweight champion Rashad Evans and The Ultimate Fighter competitor Luke Zachrich.