Ridnour's father, Rob, was his basketball coach during high school. His father gave him the keys to the gym during his sophomore year; he was able to practice during the day and late into the night. Subsequently, he was on two state title-winning teams at Blaine High School, and was named a high school All-American by both McDonald's and Parade in 2000, his graduation year.
Luke was picked 14th in the 2003 NBA draft by the Seattle SuperSonics. Luke played sparingly during his rookie season, but became the starting point guard for the Sonics in the 2004–05 season. He participated in the 2005 All-Star weekend, playing in the Rookie Challenge and in the Skills Challenge.
On August 13, 2008, Ridnour was involved in a three-team, six-player deal involving the Sonics, the Milwaukee Bucks, and the Cleveland Cavaliers, that sent Milwaukee's Mo Williams to Cleveland, Cleveland's Joe Smith and Milwaukee's Desmond Mason to Oklahoma City, Cleveland's Damon Jones and Ridnour and Adrian Griffin to Milwaukee, which ended Ridnour's five-year run with the Sonics/Thunder.
On July 21, 2010, Ridnour signed a four-year, $16 million contract with the Minnesota Timberwolves. On February 22, 2012, he scored a buzzer-beater with a floater against the Utah Jazz.
On July 25, 2014, Ridnour signed with the Orlando Magic.
Later career and retirement (2015–2016)
In June 2015, Ridnour garnered national attention as he was traded four times in the span of six days. On June 24, he was traded to the Memphis Grizzlies in exchange for the draft rights to Jānis Timma. On June 25, the Grizzlies sent him to the Charlotte Hornets in exchange for Matt Barnes; later that same day he was traded, along with a 2016 second-round draft pick, to the Oklahoma City Thunder in exchange for Jeremy Lamb. Lastly, on June 30, Ridnour was traded to the Toronto Raptors along with cash considerations in exchange for the draft rights to Tomislav Zubčić. Ridnour later stated in an interview with USA Today that he found the whole situation rather "funny", as he and his family were present at their home in Seattle while the moves were unfolding. On July 9, 2015, he was waived by the Raptors, adding to the list of teams he never visited during the two-week period. On September 21, 2015, Ridnour announced his decision to sit out the 2015–16 season. On June 22, 2016, Ridnour announced his retirement from professional basketball.
NBA career statistics
Regular season
Playoffs
Personal life
Ridnour is a Christian. Ridnour has spoken about his faith saying, "Even though I now have more success, fame, and money than I ever dreamed, my relationship with God is the only thing that brings me true peace and satisfaction."