Key facts
- Country
- United States
- State
- Michigan
- Founded
- 1822 ; 204 years ago ( 1822 ) (created), 1826 (organized)
- Named after
- O-wash-ta-nong ("far away water"), Ojibwe name for the Grand River
- Seat
- Ann Arbor
- Largest city
- Ann Arbor
- Total
- 722 sq mi (1,870 km )
- Land
- 706 sq mi (1,830 km )
- Water
- 16 sq mi (41 km ) 2.3%
- Estimate 2025
- 370,214
- Density
- 527/sq mi (203/km )
- Time zone
- UTC−5 ( Eastern )
- Summer dst
Article
Washtenaw County (/ˈwɔːʃtənɔː/ WAWSH-tə-naw) is a county located in the U.S. state of Michigan. At the 2020 census, the population was 372,258. The county seat and largest city is Ann Arbor. The county was authorized by legislation in 1822 and organized as a county in 1826. Washtenaw County comprises the Ann Arbor Metropolitan Statistical Area. The county is home to the University of Michigan, Eastern Michigan University, Washtenaw Community College, and Concordia University Ann Arbor.
History