Mark Tollefsen (born November 21, 1992) is an American professional basketball player who last played for Maccabi Ashdod of the Israeli Premier League. He played college basketball for the University of San Francisco and University of Arizona before playing professionally in Estonia and Israel. In 2018–19, he was the top scorer in the Israel Basketball Premier League.

Tollefsen attended San Ramon Valley High School in Danville, California, where he earned third-team All-East Bay and All-Metro honors after shooting 54.0 percent from the floor and 45.0 percent from the arc as a senior. Tollefsen helped lead San Ramon to a 28–4 record and a share of the EBAL title as a junior.^[1]

Tollefsen played college basketball at San Francisco, where he averaged 13.9 points, 5.4 rebounds and 1.5 assists in his junior year. He was ranked fifth in the WCC in field goal percentage (.535), 10th in scoring average and 15th in rebounding average.^[1] On March 8, 2015, Tollefsen was named to the second-team All-West Coast Conference.^[2]

On April 27, 2015, Tollefsen transferred from San Francisco to Arizona as a graduate transfer.^[3] In his senior year at Arizona, he averaged 7 points and 3 rebounds and 1.2 assists while appearing in all 34 games with 13 starts.^[1]