As a junior and senior playing college basketball for the Oregon State Beavers, Payton was named first-team All-Pac-12 as well as Pac-12 Defensive Player of the Year.

[2] During Payton's sophomore season at Salt Lake CC he signed a letter of intent to play for his father's alma mater Oregon State under coach Craig Robinson.

[8] Robinson was fired before the start of the 2014–15 basketball season and was replaced by University of Montana head coach Wayne Tinkle.

His father, Hall of Famer Gary Payton, is the other Beaver with a triple-double when he had 20 points, 14 rebounds and 11 assists against the University of Portland in 1988.

[19] On October 31, 2016, he was acquired by the Rio Grande Valley Vipers of the NBA Development League as an affiliate player of the Rockets.

[24] On October 17, 2017, Payton II was given a two-way contract with the Bucks via their NBA G League affiliate the Wisconsin Herd, meaning he would officially return to Milwaukee for the start of the season.

[28] On December 12, 2018, the Rio Grande Valley Vipers of the NBA G League announced via Twitter that they had re-acquired Payton.

[33] On October 24, 2019, the Canton Charge acquired the returning right from Rio Grande Valley Vipers for Payton in exchange for Jaron Blossomgame.

[39] On January 11, 2021, Payton was selected 15th overall by the Raptors 905 in the NBA G League draft,[40] where he averaged 10.8 points on 55.5 percent shooting from the field, 5.6 rebounds, 2.6 assists and 2.54 steals in 21.9 minutes per game.

[41] At the end of the shortened single-site season in Orlando, he was named the 2021 NBA G League Defensive Player of the Year.

In Game 2, he fractured his left elbow when he went up for a fast-break layup but fell hard after the Grizzlies' Dillon Brooks chased him down and hit him in the head while he was in the air.

On January 2, 2023, Payton made his Blazers debut, putting up seven points, four assists, two rebounds, and one steal in a 135–106 win over the Detroit Pistons.

[54] On February 9, 2023, Payton was traded back to the Golden State Warriors alongside two second-round picks in a four-team trade involving the Atlanta Hawks and Detroit Pistons, sending Kevin Knox II and five second-round picks to Portland, James Wiseman to Detroit and Saddiq Bey to Atlanta and made his debut on March 26, against the Minnesota Timberwolves.