On January 14, 2022, Charbonnet announced that he would return to UCLA in 2022 for his senior season. On October 8, he rushed for a career-high 198 yards and a touchdown on 22 carries in a 42–32 win over No. 11 Utah. He tied his career-high against with 198 yards rushing in a win against Stanford, rushing for three touchdowns while also leading the team with five receptions for 61 yards. Charbonnet finished the season with 1,359 yards rushing and 14 touchdowns, while catching 37 passes for 321 yards. He was named a first-team All-American as an all-purpose specialist by the Football Writers Association of America. He led the nation with 168 all-purpose yards per game. His 1,680 all-purpose yards were the eighth-highest single-season total in UCLA history. After the season, Charbonnet declared for the 2023 NFL Draft, forgoing his remaining year of eligiblity, which was granted by the NCAA for all players on a roster during the 2020 season impacted by the COVID-19 pandemic.
