Emmett played college basketball for 4 years for Bob Knight at Texas Tech University. He is currently the Red Raiders' 2nd all-time leading scorer and the 4th all-time leading scorer in the Big 12 behind Buddy Hield, LaceDarius Dunn, and fellow Red Raider Jarrius Jackson with 2,256 points. During his freshman year and playing for Coach James Dickey, Emmett earned his way into the starting lineup averaging 7.7 points and 3.6 Rebounds per game. When Bob Knight arrived at Texas Tech in 2001, Emmett saw his scoring average improve to 18.7 which was good enough for 3rd in the conference behind Drew Gooden and Kareem Rush and 1st team All-Big 12 honors. His junior and senior year, Emmett proved to be one of the best scorers in college basketball averaging 21.8 and 20.6 points per game, respectively. He also earned Unanimous 1st team All-Big 12 honors his junior and senior year and Consensus All-American honors his senior year. Emmett capped off his college career by winning the 2004 NCAA Slam Dunk Contest.
Emmett was selected by the Seattle SuperSonics with the 35th overall pick in the 2004 NBA draft. He was later traded to the Memphis Grizzlies in a draft night trade. He joined the Grizzlies for 2004 NBA Summer League. On July 7, 2004, he signed his first professional contract with the Grizzlies. In the 2004–05 season, he played a total of 8 games for the Grizzlies.
Emmett re-joined the Grizzlies for the 2005 NBA Summer League. On August 3, 2005, Emmett was traded to the Miami Heat in a five-team trade involving the Memphis Grizzlies, Miami Heat, Boston Celtics, Utah Jazz, and New Orleans Hornets. On October 31, 2005, he was waived by the Heat. In November 2005, he was acquired by the Austin Toros of the NBA D-League.
In July 2006, Emmett joined the Dallas Mavericks for the Las Vegas Summer League and the Seattle SuperSonics for the Rocky Mountain Revue. Later that year, he signed with Lietuvos rytas of Lithuania for the 2006–07 season. In December 2006, he left Lietuvos. On January 19, 2007, he was acquired by the Los Angeles D-Fenders.
Emmett joined the Houston Rockets for the 2007 NBA Summer League. In December 2007, he signed with the Liège Basket of Belgium for the rest of the 2007–08 season, subsequently finishing the best scorer (23.9 ppg) of the Belgian championship.
Emmett joined the Indiana Pacers for the 2008 NBA Summer League. On September 29, 2008, he signed with the Philadelphia 76ers. However, he was waived by the 76ers on October 6. Later that month, he joined Élan Béarnais Pau-Orthez of France for the 2008–09 season. In January 2009, he left Pau-Orthez after playing in only 5 games. He later joined Marinos de Anzoátegui for the 2009 LPB season.
In November 2009, he signed with the Shandong Lions of China for the 2009–10 season. In March 2010, he scored a (then) CBA-record 71 points in a game against the Jiangsu Dragons. Following the CBA season, he joined Mets de Guaynabo for the rest of the 2010 BSN season.
In December 2010, he signed with Fujian Xunxing of China for the rest of the 2010–11 season. On March 25, 2011, he was acquired by the Reno Bighorns.
On December 15, 2011, he was re-acquired by the Bighorns. On February 14, 2012, he signed a 10-day contract with the New Jersey Nets. On February 24, 2012, he returned to the Bighorns. In April 2012, he signed with Sporting Al Riyadi Beirut of Lebanon for the 2012 FLB League playoffs.
Emmett joined the NBA D-League Select Team for the 2012 NBA Summer League. On October 1, 2012, he signed with the Chicago Bulls. However, he was waived by the Bulls on October 15.
In December 2012, Emmett signed with Amchit Club of Lebanon for the rest of the 2012–13 season. Following the FLB League season, he joined Cocodrilos de Caracas for the 2013 LPB season, but left after 5 games.
In January 2014, Emmett joined Cocodrilos de Caracas for the 2014 FIBA Americas League. In April 2014, he joined Halcones Rojos Veracruz of Mexico before re-joining Cocodrilos de Caracas for the 2014 LPB season. On July 13, 2014, he signed with Piratas de Quebradillas of the BSN where he played one game.
On November 1, 2014, Emmett was selected by the Fort Wayne Mad Ants in the second round of the 2014 NBA D-League draft. On February 4, 2015, he was named to the Futures All-Star team for the 2015 NBA D-League All-Star Game, the second time in his career. He went on to record 28 points, 4 rebounds and 4 Steals, and was subsequently named the All-Star Game MVP.
In March 5, 2015 Andre Emmett left the Mad Ants and signed with the Meralco Bolts of the Philippine Basketball Association for the 2015 Governor's Cup campaign.
On July 22, 2015, Emmett was selected by the KCC EGIS(전주 KCC 이지스) with the 5th overall pick in the 2015 KBL foreigner draft. Emmett is preparing for his first season in South Korea.