Hamilton was selected with the 26th overall pick in the 2011 NBA draft by the Dallas Mavericks. His draft rights were later traded to the Denver Nuggets on draft night. On December 9, 2011, he signed with the Nuggets. On January 3, 2012, he was assigned to the Idaho Stampede. On January 15, 2012, he was recalled by the Nuggets.
On August 18, 2014, Hamilton signed with the Toronto Raptors. However, he was later waived by the Raptors on October 25, 2014. Two days later, he was claimed off waivers by the Utah Jazz. On November 6, 2014, he was waived by the Jazz before appearing in a game for them. On November 26, 2014, he was acquired by the Iowa Energy of the NBA Development League. On December 10, 2014, Hamilton was traded, along with a 2015 second-round pick, to the Reno Bighorns in exchange for a 2015 first-round pick. On February 4, 2015, he was named to the Futures All-Star team for the 2015 NBA D-League All-Star Game.
On February 24, 2015, Hamilton signed a 10-day contract with the Los Angeles Clippers. On March 6, 2015, he signed a second 10-day contract with the Clippers. On March 20, he signed with the Clippers for the remainder of the season.