Interstate 675 (I-675) is an auxiliary Interstate Highway in the US state of Michigan. The freeway is a 7.7-mile-long (12.4 km) loop route through downtown Saginaw, as I-75 passes on the east side of the city. I-675 is also a state trunkline highway that provided a bypass of the former drawbridge carrying I-75 and US Highway 23 (US 23) across the Saginaw River. Construction of I-675 started in 1969 and the freeway opened in 1971. Since then, sections near downtown were reconstructed between 2009 and 2011 to update one of the freeway's interchanges and rebuild the bridge over the Saginaw River.

Saginaw is a city in and the seat of Saginaw County, Michigan, United States. The city proper had a population of 44,202 at the 2020 census. Located along the Saginaw River, Saginaw is adjacent to Saginaw Charter Township and considered part of Greater Tri-Cities region of Central Michigan. The Saginaw metropolitan area had a population of 190,124 in 2020. The city is also the largest municipality in the Greater Tri-Cities, with a combined population of 377,474 in the combined statistical area in 2020.