Kevin Casey began training in BJJ back in 1999 when he became friends with Rockson Gracie, the son of legend Rickson Gracie. He was given his black belt in 2010 by Kron and Rickson Gracie. He compiled a 5-2 MMA record and fought once for Strikeforce in a losing effort to Matt Lindland.

Casey would try out for the 17th season of The Ultimate Fighter and would punch his ticket into the house with a rear naked choke in the first round over Eldon Sproat. Casey was the 5th person selected to join Team Sonnen.

In the 3rd episode of the season Kevin Casey was selected by Chael Sonnen to fight Collin Hart, Team Jones' 5th round pick. In the fight with Collin Hart he was controlled for most of the fight and lost a 20-18 decision.  He would get another shot when he was chosen as the wild card to face Bubba McDaniels.  He would lose the fight when he was unable to continue claiming afterwords that it was kidney failure. Casey was put on The Ultimate Fighter 17 Finale to face Josh Samman.  He lost the fight by TKO in the second round and was cut from the promotion after his loss.

Casey then signed with RFA, and after securing wins over Casey Ryan and Eddie Mendez, became the promotion's middleweight champion with a first round finish over Andrew Sanchez.  Only one month after picking up the title, Casey re-signed with the UFC and was matched up against newcomer Bubba Bush.  Casey scored another quick first round finish, but it was later overturned to a No Contest after Casey failed his drug test for the bout.

The Ultimate Fighter: Team Jones vs. Team Sonnen

Episode 1 Casey def. Eldon Sproat by Submission (rear-naked choke) (2012.10.30)

Episode 4 Collin Hart def. Casey by Unanimous Decision (2012.11.13)

Episode 9 Bubba McDaniel def. Casey by TKO (retirement) in Round 2 (2012.11.27)