Franklin was selected with the 10th overall pick in the 2006 NBA draft by the Seattle SuperSonics and has also played for the Oklahoma City Thunder, Atlanta Hawks, and Milwaukee Bucks.
Despite being diagnosed with Marfan syndrome, a potentially life-threatening genetic disorder that affects the body’s connective tissue, Franklin went on to play basketball at the University of Washington and was selected 10th overall in the 2006 NBA draft by the SuperSonics (who would become the Oklahoma City Thunder just days later). He holds career averages of 14.9 points, 4.1 rebounds, and 2.3 assists in 272 games played.
In college, Franklin was a two-time All-Pac-10 First Team selection and a Third Team All American as a sophomore by various media outlets. As a freshman, he had been selected Honorable Mention All Pac-10 while being named the Most Outstanding Freshman in the conference. As a sophomore, he helped lead the Huskies to the Sweet Sixteen round of the NCAA Tournament by averaging 20 points per game in three games before losing against Georgia Tech.
On June 28, 2010, Franklin signed with the Oklahoma City Thunder. On February 21, 2011, he was traded to the Atlanta Hawks in exchange for the draft rights to Georgios Printezis.
After playing for the Hawks in 2011, he was traded on February 23, 2012, to the Los Angeles Lakers along with a 2012 first-round pick and an option to swap second-round picks in 2013 for Joe Smith and the draft rights to Sergei Lishouk. The Lakers then waived him. He signed with the Golden State Warriors on March 1.
On September 11, 2012, Franklin was traded to the Houston Rockets in exchange for Tyler Honeycutt. On January 17, 2013, he was waived by the Rockets after playing only six games during the 2012–13 season. The following month, he joined the Tianjin Ronggang of China for the 2013 NBL season.
On September 30, 2013, Franklin signed with the Toronto Raptors. On December 9, he was waived by the Raptors after appearing in seven games. On January 16, 2014, Franklin signed with Limoges CSP for the rest of the 2013–14 LNB Pro A season. On March 18, he parted ways with Limoges after suffering a season-ending knee injury.
On September 24, 2014, Franklin signed a one-year deal with the Sydney Kings of the National Basketball League.
In April 2018, Franklin joined three former NBL players as part of a team that went on an exhibition tour of China. He joined Perry Ellis, David Andersen, and Nathan Jawai as part of the team that was coached by Shane Heal.
Franklin has won gold medals with USA Basketball at the 2007 FIBA Americas Championship and 2008 Beijing Olympics. He helped lead Team USA to a bronze medal at the 2012 London Olympics, where he averaged 11.5 points in five games.