Chelsea is a city in Washtenaw County in the U.S. state of Michigan. The population was 4,398 at the 2000 census, at which time it was a village. In March 2004, by a 995-226 vote, residents approved a change in municipal status from a village into a city. Residents no longer pay property taxes to adjacent Lima Township and Sylvan Township as they had under the village government. The city provides all services formerly provided by both village and township governments.