Donald P. Garber (born October 9, 1957) is an American sports executive who has been the commissioner of Major League Soccer (MLS) since 1999. Garber is also the CEO of Soccer United Marketing and a member of the United States Soccer Federation board of directors.

Garber has spent his entire career in the sports industry, working in a variety of capacities in marketing, events, television, and league administration prior to becoming MLS commissioner. Before joining MLS, Garber was with the National Football League (NFL) for 16 years.

Under his leadership, MLS has experienced sustained growth in size and popularity in the United States and Canada. During his tenure, MLS has expanded from 10 to 30 teams and set records for attendance and broadcast revenue. In addition, the league has seen significant increases in every metric – including team valuations, attendance, sponsorship, and digital and social media engagement. MLS ranks seventh among global soccer leagues in average game attendance.

Garber grew up in a second generation Jewish family. His mother's parents were communists from Russia; his father's were Orthodox Jews from Poland. Garber's mother worked as a nursery school teacher and Garber's father as an accountant. He grew up in Queens, New York, during the 1960s and 1970s.

Garber has been selected by SportsBusiness Journal as one of the sports industry's most powerful executives every year since 2005. In 2022, he was 16th on the list. In 2016, SportsBusiness Journal presented MLS with its award for League of the Year. In May 2019, Garber was named the Sports Business Journal Executive of the Year. In 2021, SBJ named the MLS is Back Tournament – when the league became the second major U.S. team sports league to return to play during the pandemic, after the National Women's Soccer League (NWSL) – the Sports Event of the Year. Garber has received numerous other industry honors, and in 2011 was named by the Los Angeles Times as one of the top sports commissioners. He has received an Honorary Doctorate of Humane Letters from both Montclair State University and the State University of New York. Garber was also inducted into the Athletic Hall of Fame at his alma mater, SUNY Oneonta. Garber was elected into the National Soccer Hall of Fame in 2016, but deferred his enshrinement until 2018. In 2023, Garber received the Werner Fricker Award – U.S. Soccer's highest honor for an individual.

Garber spent 16 years with the National Football League, finishing his tenure as the senior vice president/managing director of NFL International, where he oversaw all aspects of the NFL's business outside the United States, including the NFL Europe League. Garber began his career at NFL Properties in 1984 as a marketing manager and became the League's director of marketing in 1988. In 1992, he was appointed the NFL's senior vice president of business development and was responsible for a variety of television, special event and marketing activities.

Garber was appointed as Major League Soccer commissioner on August 4, 1999, succeeding Doug Logan. One of his first moves as commissioner was to bring the league more in line with the international standard, eliminating the shootout and having the referee keep the time on the field. In 2004, MLS also eliminated overtime and the three-plus-one substitution rule. This enabled teams to substitute three field players as well as an additional goalkeeper. "This decision reflects our focus on continuing our alignment with the world's game," said Garber at the time.

Garber has emphasized gradual, sustained growth of the league over decades rather than attempting grandiose moves to win headlines. Before Garber came into the Commissioner's office, the league had only one team in its own stadium, Columbus Crew, whose Columbus Crew Stadium was built by Lamar Hunt in 1999.