Tawas City is a city in and county seat of Iosco County in the U.S. state of Michigan. The population was 1,834 at the 2020 census. The city is …Tawas City is a city in and county seat of Iosco County in the U.S. state of Michigan. The population was 1,834 at the 2020 census. The city is mostly surrounded by Tawas Township, but the two areas are administered autonomously.