Miles attended Skyline High School for Architecture in Dallas, where he was named to the Parade All-American First Team.

Miles led Skyline to the Class 5A Region II quarterfinals as a senior and was named All-Dallas Area Player of the Year by The Dallas Morning News.

34 jersey making him only the second player in school history to receive the honor, joining former NBA star Larry Johnson.

Miles committed to the University of Texas at Austin, stating that if he was not selected in the first round of the NBA draft he would play for the Longhorns.

[1] During the 2005–06 season, the Jazz assigned Miles to the Albuquerque Thunderbirds of the NBA Development League (D-League) in order for him to attain more experience.

[3] Miles is known as the subject of one of the most memorable post-game interviews of the 2006–07 NBA season, where coach Jerry Sloan stated, "I don't care if he's 19 or 30.

[13][14] In his debut for the Raptors in their season opener on October 19, 2017, Miles scored 22 points in a 117–100 win over the Chicago Bulls.

[15] On February 7, 2019, Miles was traded, along with Jonas Valančiūnas, Delon Wright and a 2024 second-round draft pick, to the Memphis Grizzlies in exchange for Marc Gasol.

[17] On December 4, 2019, the Wizards announced that Miles had undergone successful surgery to repair ligament damage in his left wrist and would be sidelined.

[23] In 2010, Miles began dating Lauren Smith while she was playing college basketball as a senior at Texas A&M University–Corpus Christi.