Daniels was a five-star recruit and ranked as the number one overall recruit in his class by Rivals.com prior to his reclassification. He committed to the University of Southern California (USC) to play college football. In December 2017, Daniels announced that he would graduate early from high school and reclassify to the 2018 class. He enrolled in USC in June 2018 upon completion of his high school course work. In August 2018, he began USC's two week fall camp in a three-way competition for the starting quarterback position. Within three weeks, Daniels was named the starter over incumbents Matt Fink and Jack Sears, making him the second true freshman in school history to start a season opener. In his true freshman year, Daniels passed for 2,672 yards, 14 touchdowns, and ten interceptions in 11 games, missing just one game due to concussion. The Trojans went 5–7 for the season.