The Los Angeles Daily News reported that Carroll, who has built one of the top programs in the college ranks in his five years at the Pac-10 school, will get about $3 million annually.
Before taking the USC post, Carroll had NFL head coaching stints with the New York Jets and New England.
"There's so much speculation (about a return to the NFL) and I know the rush is going to hit me again," Carroll told the newspaper. "It's a good time to let everyone know. There will be a lot of movement in the NFL and I've been subject to a lot of speculation."
Under Carroll, the Trojans, 12-0 and ranked No. 1 all season, have built a 34-game winning streak and will play for their third consecutive national title against second-ranked Texas in the Rose Bowl on Jan. 4.