Lee turned professional in 2010 and joined the OneAsia Tour for 2011, earning his card through qualifying school.

[6] At the 2021 Waste Management Phoenix Open, Lee finished in a tie for second, one stroke behind winner, Brooks Koepka.

[7] Three months later, Lee earned his first PGA Tour win at the 2021 AT&T Byron Nelson, with a score of 25-under-par, beating runner-up Sam Burns by three strokes.

[8] A year later, Lee successfully defended his title at the AT&T Byron Nelson, shooting 26-under-par; beating Jordan Spieth by one shot.

[9] In September 2022, Lee was selected for the International team in the 2022 Presidents Cup; he won two and lost one of the three matches he played.