The Cleveland County Sheriff's Office said Carl "Chuck" Goff Jr., 54, was killed in the crash Wednesday night in the rural county, about 35 miles south of Oklahoma City.
Keith said in a statement that he's "deeply saddened" by Goff's death. Keith said Goff was a close friend for more than 25 years, serving as band leader and bass player.
Goff shared writing credits on "Upstairs Downtown" and "You Ain't Much Fun" on Keith's 1994 album "Boomtown."
The two-vehicle crash remained under investigation. Authorities said the driver of the second vehicle wasn't seriously injured.