The school wasted no time selecting Ault after Chris Tormey was fired Sunday, one day after Nevada concluded a 6-6 season with a 56-3 drubbing at Boise State.
Ault is the winningest coach in Nevada history, posting a 163-63-1 record from 1976-92 and 1994-95. He is stepping down as the Wolf Pack's athletic director, a position he had held since 1986.
Ault was inducted to the Hall of Fame last year. He earned national Coach of the Year honors in 1978 and 1991.
"We're losing a top-notch athletics director but we are gaining a Hall of Fame coach who gives our program an immediate national identity," Nevada President John Lilley said.