In his first season with the Raptors, Parker helped the team clinch their first-ever division title, first NBA playoffs berth in five years, and best regular-season record in franchise history.

[5] He then played college basketball at Bradley University where he established himself as a top player, averaging 18.9 points per game (ppg) and shooting 42% from the three-point line in his third season,[6] earning the Missouri Valley Conference (MVC) Most Valuable Player and All-MVC first team honors in the same season.

[7] His outstanding performances for the Braves ensured that he became one of 15 players honored in Bradley's All-Century basketball team named in 2003.

[11] He finished the remainder of the season with the Quad City Thunder of the Continental Basketball Association where he averaged 11.5 points in 26 games.

[12] Eventually, he moved to Israel in the 2000–01 season, where he was signed by the Israeli EuroLeague powerhouse Maccabi Tel Aviv.

Parker was signed to fill the void left by Doron Sheffer's retirement at the shooting guard position, but ended up featuring as both a scorer and play-maker for Maccabi.

[12] He immediately brought to the team his ability to score, rebound, block shots, and even entertain the crowds with slam dunks.

[15] He was signed for approximately $12 million (USD) over three years,[12] joining recent European veteran acquisitions Jorge Garbajosa and José Calderón on the team.

[5] Parker's defensive and offensive versatility were credited as instrumental in helping the Raptors clinch their first-ever division title, first NBA playoffs berth in five years, as well as best regular-season record in franchise history.

In the first round of the 2007 NBA Playoffs, Parker was chosen to defend New Jersey Net and former Toronto favorite Vince Carter.

[26] In the 2007–08 season, Parker remained—despite the signing of Miami's Jason Kapono—the starting shooting guard for the Raptors, with rookie Jamario Moon completing the wing positions.

First, Kapono was temporarily moved to the starting shooting guard spot after the Raptors fired head coach Sam Mitchell.

Although Parker eventually regained his starting spot, Toronto fell further behind the playoff race as a result of changing rosters and inconsistent performances, dropping to 21–34 just before the All-Star break.

The Raptors eventually concluded the regular season with only 33 wins,[30] with Parker suffering a significant drop in his numbers (shooting percentage and points per game).

"[34] In a bid to ensure that James had his best shot of winning a title before he could potentially become a free agent after the season, Cleveland also acquired Shaquille O'Neal and subsequently, Antawn Jamison, both of whom were veteran superstars.

During the 2010 NBA offseason, LeBron James and Zydrunas Ilgauskas left Cleveland for the Miami Heat, which led several other veterans to also leave the team.

The departures would thrust Parker, Antawn Jamison and Anderson Varejão into the spotlight as the veteran leaders for the young team.

While Cleveland only managed a conference-worst 19–63 season, they were able to upset LeBron James' heavily favored Miami Heat on March 29, 2011, in a game where Parker grabbed eight rebounds and scored 20 points.

[37] Parker had a brief stint with the junior United States men's national basketball team, as a college player.

[38] Parker was the scout of the Orlando Magic following his retirement in 2012 and fulfilled that role until 2017, when he was promoted to become the G League general manager.