Browning attended Folsom High School in Folsom, California. At Folsom, Browning had a 4.0 GPA, was active in clubs, and set numerous national and state records during his high school career. In 46 games, he completed 1,191 of 1,708 attempts for 16,775 yards and 229 touchdowns, all California records. The 229 touchdowns also broke the national record previously held by Maty Mauk who had 219. As a senior, he threw for a national-record 91 touchdown passes. He also passed for a California-record 5,790 yards, which broke his record from his junior year. Browning was the Gatorade Football Player of the Year during his junior and senior years.
In his first year at Washington, Browning became the second ever (in any game) true freshman to start at the quarterback position at UW (the other was Marques Tuiasosopo vs. Oregon in 1997) and the first true freshman to start a season opener for the Huskies. In his first career start, he completed 20 of 34 passes for 150 yards and one interception.
In his sophomore year, Browning performed on a much higher level, guiding UW to a 12–2 record, and the Huskies first conference championship since 2000. He set a new record for touchdowns per attempt at 12.2%. On November 29, he was named Pac-12 Offensive Player of the Year and first team all-Pac-12. Browning came in sixth in the 2016 Heisman Trophy voting, narrowly missing an invitation to attend the award ceremony in New York City. His sixth-place finish is the second best Heisman voting finish in school history, behind only Steve Emtman who finished fourth.
Browning underwent shoulder surgery on his throwing arm a couple weeks after facing Alabama in the College Football Playoff. His injury was kept secret for nearly two months, and some commentators have speculated as to a connection between the injury and Browning's reduced performance in the latter portion of the season.