Herro was born in Greenfield, Wisconsin, where he attended Whitnall High School. In his senior year, he was named to the First Team All-State after averaging an incredible 32.9 points, 7.4 rebounds, 3.6 assists, and 3.3 steals per game. He finished his high school career with more than 2,000 points, cementing his reputation as one of the top prospects in the country.

Despite receiving scholarship offers from several top schools, including the University of Wisconsin and Marquette University, Herro committed to play for Wisconsin in September 2016. However, that commitment was short-lived, as he de-committed from Wisconsin in October 2017 after being recruited by Kentucky and the University of Kansas.

Ultimately, Herro decided to play for the University of Kentucky, where he quickly established himself as one of the top players in the nation. In his freshman year, he averaged 14.0 points, 4.5 rebounds, and 2.5 assists per game, and helped lead the Wildcats to the Elite Eight of the NCAA Tournament. After just one year at Kentucky, Herro declared for the 2019 NBA draft and was selected 13th overall by the Miami Heat.

Since joining the Heat, Herro has continued to impress, averaging 14.2 points, 4.1 rebounds, and 2.4 assists per game in his rookie season. He quickly became a fan favorite in Miami and helped lead the Heat to the NBA Finals in 2020, where they ultimately fell to the Los Angeles Lakers.