Stoops is stepping down.

FOX's Chris Hoenig reports:

Oklahoma football coach Bob Stoops is retiring after 18 seasons, ending the career of the longest-tenured coach in college football.

The 56-year-old was a rookie head coach when he took over the Sooners in 1999, leading them to a national title the very next year, as well as 10 Big 12 titles and bowl games in all 18 seasons.

Stoops finishes as OU's winningest coach ever, with a record of 190 wins and 48 losses, that includes 14 seasons with at least 10 wins, and three other trips to the BCS National Championship game.

He was named the Walter Camp Coach of the Year in 2000 and 2003, and won the Big 12 Coach of the Year award six different times.

33-year-old offensive coordinator Lincoln Riley will take over.

Chris Hoenig, FOX News.

Follow Chris Hoenig on Twitter: @Chris_Hoenig