Mark P. Begich (pronounced /ˈbɛɡɪtʃ/; born March 30, 1962) is the junior United States Senator from Alaska and a member of the Democratic Party. A former mayor of Anchorage, he served on the Anchorage Assembly for ten years before being elected mayor in 2003. In the highly competitive 2008 Alaska Senate election, Begich defeated incumbent Ted Stevens, the longest serving Republican member of the Senate at the time.

Begich was born in Anchorage at the Old Providence Hospital, and is the first person born in Anchorage to be elected as the city's mayor. He is the son of U.S. Representative Nick Begich, who disappeared in a plane over Alaska with U.S. House Majority Leader Hale Boggs in 1972. The fourth child of six born to Nick and Pegge Begich; he has two sisters and three brothers. His Croatian paternal grandfather John Begich immigrated to the United States from Austria–Hungary in 1911. He attended Steller Secondary School in Anchorage. Begich has taken continuing education classes at University of Alaska Anchorage without graduating. Begich is the only U.S. Senator without a college degree. In 1990, he married Deborah Bonito, a former chair of the Alaska Democratic Party, and the current owner of several small businesses throughout Anchorage. The Begiches have a son, Jacob, who was born in July 2002.

Begich was elected to the Anchorage Assembly in 1988, at age 26, and served until 1998, including three years as chairman and two as vice chairman. In 1989, Begich led the opposition to the sale of the municipally-owned Anchorage Telephone Utility (ATU) to private interests. ATU was eventually sold in 1999 (after Begich had left the Assembly). Begich was also one of the chief sponsors of the introduction of photo radar.