Ann Arbor is a city in the U.S. state of Michigan and the county seat of Washtenaw County. The 2010 census places the population at 113,934, making it the sixth largest city in Michigan. The Ann Arbor Metropolitan Statistical Area (MSA) had a population of 344,791 as of 2010. The city is also part of the larger Detroit – Ann Arbor – Flint, MI CSA.

Ann Arbor was founded in 1824, with one theory stating that it is named after the spouses of the city's founders and for the stands of trees in the area. The University of Michigan moved from Detroit to Ann Arbor in 1837, and the city showed steady growth throughout the 19th and 20th centuries, with a decline during the Depression of 1873. During the 1960s and 1970s, the city gained a reputation as an important center for liberal politics. Ann Arbor also became a focal-point for left-wing activism and served as a hub for the civil-rights movement and anti-Vietnam War movement, as well as the student movement.

Ann Arbor is home to the University of Michigan, a world renowned institution of higher education. The university shapes Ann Arbor's economy significantly as it employs about 30,000 workers, including about 12,000 in the medical center. The city's economy is also centered on high technology, with several companies drawn to the area by the university's research and development money, and by its graduates. In the year 2010, Forbes listed Ann Arbor as one of the most liveable cities in the United States of America.