Teaming with fellow Iowan Kirk Hinrich to form one of the best duos in college basketball, Collison helped the University of Kansas reach two consecutive Final Fours (2002 and 2003).

Collison finished his college career as the leading scorer in the history of the Big 12 Conference (a mark since surpassed).

[2] Collison was selected by the Seattle SuperSonics with the 12th overall pick in the 2003 NBA draft but missed the 2003–04 season with injuries to both shoulders.

He made his NBA debut on November 3, 2004, recording two points, five rebounds and two assists in a 114–84 loss to the Los Angeles Clippers.

[5] That postseason, on May 15, 2011, Collison helped the Thunder to a Western Conference Semifinals Game 7 win over the Memphis Grizzlies, with eight points and a playoff career-high 12 rebounds.

[9][10] Collison's final NBA game was played on April 11, 2018, a 137–123 win over the Memphis Grizzlies where he recorded one point and one rebound.

[17][18] His younger brother, Michael, played college basketball for their father's alma mater, Briar Cliff University, in Sioux City, Iowa.