Marcus Alexander Thornton (born February 9, 1993) is an American professional basketball player for the Astros de Jalisco of the Mexican CIBACOPA.

Thornton completed his collegiate career at the College of William & Mary (W&M) in 2015 and was named the 2014–15 Colonial Athletic Association Player of the Year.

On February 25, 2015, Thornton surpassed 2,052 career points to overtake Chet Giermak's long-standing school record.

Giermak's mark stood for 65 years – the longest-lasting NCAA Division I school record in the nation at the time it was broken.

[1] Thornton, a native of Upper Marlboro, Maryland, fell in love with basketball at an early age and was considered very talented throughout his youth.

[2] He attended Bishop McNamara High School, a perennial basketball power, not because of the sport but because of its academic reputation and its proximity to his home.

[2] Although Christian ended up taking an assistant coaching job at VCU the spring before Thornton enrolled, it did not affect his decision to attend.

[3][5] He increased his scoring to 18.8 points per game in 2012–13 while he began to establish himself as a player who could create his own shot late in a possession.

[3][6] The Tribe lost by one point to Delaware, 75 to 74, barely missing out on the program's first-ever NCAA tournament appearance.

[3][8] Entering his senior season, Thornton was selected by the league's coaches as the preseason CAA Player of the Year.

[8] He also entered 2014–15 as the only returning All-CAA First Team player with a legitimate shot at breaking the school's scoring mark of 2,052.

[2][9] Thornton guided the Tribe to a 12–6 CAA record as they finished in a four-way tie for the regular season conference championship with James Madison, Northeastern, and UNC Wilmington.

By owning the regular season tie-breakers over the other three co-champions, William & Mary earned the automatic National Invitation Tournament (NIT) bid, making the 2015 appearance their third in school history.

[13] He also set the single season three-point field goals made (102) and most career games played (127 – tied) records.

[21] Four days later, he made his debut for Maine in a 122–106 win over Raptors 905, recording seven points, one rebound, three assists and one steal in 15 minutes.

[31] In his two seasons in Germany's top-tier league for Niners Chemnitz and Medi Bayreuth, Thornton averaged a convincing 13.2 points, 3.5 assists, and 1.9 rebounds across 58 games.