Kiffin, the son of Tampa Bay defensive coordinator Monte Kiffin, earned the job with a strong interview Monday after the Raiders failed to reach a deal last week with 32-year-old Steve Sarkisian, Kiffin's fellow assistant to Pete Carroll at USC.
The Raiders called a news conference for Tuesday to announce the hiring.
Raiders owner Al Davis quickly moved to land another up-and-coming offensive mind with sterling college credentials, but just one season of NFL experience — as a defensive quality control coach with Jacksonville in 2000.
At 31 years, 8 months, Kiffin is even younger than Harland Svare, who took over the Los Angeles Rams in 1962 at 31 years, 11 months. Svare is listed by the Pro Football Hall of Fame's Web site as the youngest coach in the modern era, though younger coaches — including George Halas — led teams during the league's founding years.
But Davis has ample reason to trust in young minds: Jon Gruden, Mike Shanahan and John Madden all succeeded as Raiders head coaches in their 30s — as did Davis.
Kiffin is 14 months younger than Madden was when the Hall of Fame coach took over the Raiders in 1969. Davis was 33 years, 6 months when he took charge of the Raiders in 1963.
Kiffin, a former Fresno State quarterback, is younger than at least nine players who finished the season with Oakland during its NFL-worst 2-14 campaign, including defensive tackle Warren Sapp, fullback Zack Crockett and receiver Alvis Whitted.
Coach Art Shell was fired after the season, and Davis apparently was determined to hire another young offensive-minded coach in the mold of Gruden, his last successful hire. Davis has fired three coaches in the last four years: Bill Callahan, Norv Turner and Shell, whose return to the Raiders lasted just one year.
Kiffin had been at USC for six years, ascending from a job as tight ends coach to three jobs last season as offensive coordinator, receivers coach and recruiting coordinator. While former Raiders assistant Sarkisian coached from the sideline with Carroll last season, Kiffin called the plays from the press box for the Rose Bowl champion Trojans.
Sarkisian had two strong interviews with the Raiders last week, but decided to stay at USC on Friday night. Both claimed Sarkisian never was offered the job, though numerous media reports said Sarkisian turned the club down.
Davis first interviewed Kiffin on Thursday — apparently to explore the possibility of hiring Kiffin as the club's offensive coordinator. Kiffin returned to the Bay Area on Sunday for a second interview, this time to discuss becoming the Raiders' head coach.
Kiffin also was a finalist for the top job at the University of Minnesota earlier in the offseason.
Former New York Giants coach Jim Fassel, San Diego Chargers receivers coach James Lofton and Raiders defensive coordinator Rob Ryan also interviewed for the job.
The Raiders seem likely to invite Ryan to stay with the club after the coach helmed one of the NFL's best defenses last season. Oakland has serious personnel problems with one of the NFL's worst offenses — but the club also has the No. 1 pick in the upcoming draft.
Davis' club will get a fresh start after the worst season in his 44 years with the franchise. Kiffin, the former coordinator of USC's high-octane passing game, will be expected to revive an aerial attack that floundered despite the presence of discontented receiver Randy Moss.
Oakland's offense scored just 168 points last season — the fifth-fewest in a 16-game season in NFL history. The Raiders were sacked a league-worst 72 times and finished last in most major offensive categories despite changing offensive coordinators from Tom Walsh to John Shoop during the season.