Saginaw County, officially the County of Saginaw, is a county located in the U.S. state of Michigan. As of the 2010 census, the population was 200,169. The county seat is Saginaw. The county was created by September 10, 1822, and was fully organized on February 9, 1835. The etymology of the county's name is uncertain. It may be derived from Sace-nong or Sak-e-nong , as the Sauk tribe once lived there. Another possibility is that it comes from Chippewa words meaning "place of the outlet" –sag and ong . SeeList of Michigan county name etymologies.