Conforto attended Redmond High School in Redmond, Washington. He was named All-State and All-League after senior campaign while batting Batted .400 , finishing with five doubles, a triple, seven home runs and 19 RBI in 29 games and stealing eight bases. He was rated as the No. 3 player in the state of Washington by Baseball Northwest prior to senior year. Perfect Game USA rates him as the No. 6 player in Washington and 211th nationally. He was named to 2010 Perfect Game USA Preseason High School Underlcassmen All-American Honorable Mention team, and played in the 2010 Area Code Games in Long Beach, Calif. He earned 2010 all-state first-team honors as an infielder and was named to KingCo 4A All-League first team after his junior season. He hit .361 as a junior, finishing with five doubles, two triples and nine home runs while posting 32 RBI. He was named to KingCo 4A All-League second team after his sophomore season, and batted .310 his sophomore season, tallying two doubles, a triple and eight home runs. He drove in 21 and stole five bases. He was the teammate of current Beaver Dylan Davis while in high school. He lettered two years in football as a quarterback and free safety, and was named second-team all-state in football.