The senior, a son of NFL Hall of Famer Jerry Rice, had 791 receiving yards and 12 touchdowns this season and averaged 17.6 yards per catch. He had one remaining year of eligibility.
"Trojan Family. Thank you for taking me in and making me feel at home," Rice wrote in a tweet announcing his decision. "Through the good and bad, being a Trojan means to persevere and Fight the f--- On!"
Rice's 12 TDs were the seventh most among receivers in the country and he also showed off his explosiveness by recording four catches of 60 yards or more.
The 6-foot-3, 210-pound wideout began his college career in 2020 as a member of the Colorado Buffaloes, with whom he spent two seasons and accounted for 419 yards and five touchdowns before transferring in 2022.
He tallied 611 receiving yards and five touchdowns in his first year at USC before becoming one of quarterback Caleb Williams' top targets this season.
Rice isn't ranked among Mel Kiper's top 10 wide receiver prospects for the 2024 draft.