The 36-years-old's wife Lauran confirmed her husband's passing to TMZ.com. The cause of death was cardiac arrest due to a collapsed lung as a result of the illness.
"Corey was a loving husband and devoted father," Hill said.
"He was such a strong role model for our children, and would do anything to keep them safe and happy and healthy."
"(He was) a fighter till the end."
Hill was a part of the fifth season of "The Ultimate Fighter" competing with top namess like Nate Diaz, Joe Lauzon and Gray Maynard.
He last fought in February before suffering health problems that put him in the hospital just recently.
Hill is survived by his wife and three children.