Coldwater is a city located in the U.S. state of Michigan, serving as the county seat of Branch County. Situated in West Central Michigan near the border with Indiana, the city is mostly surrounded by Coldwater Township, though the two entities are administered autonomously. The area is defined by significant water features, including the Coldwater River which flows into the city from the south and originates from Coldwater Lake. Additionally, the Sauk River flows through the south side of the city before combining with other waterways to form a series of shallow, connected lakes on the west side.

American settlers first moved into the area around 1830, with many arriving from New York and New England. Coldwater was incorporated as a village in 1837 and later incorporated by the legislature as a city in 1861. It was designated in 1842 as the county seat of Branch County. The city has expanded since 1967 when Interstate 69 was completed, incorporating urban sprawl at exit 13. This growth was facilitated by major highways including Business Loop I-69, which runs through downtown, and U.S. Highway 12.

The city features historic architecture and notable landmarks that define its character. The Tibbits Opera House, built in 1882 in the French Empire style, is the second-oldest theater in Michigan and now serves as a venue for cultural activities. The Wing House, constructed in 1875, operates as a historical museum by the Branch County Historical Society. Other points of interest include the Children's Museum of Branch County and Waterworks Park, which offers riverfront access along the Sauk River. Heritage Park provides tennis courts for visitors.

Coldwater hosts several seasonal annual festivals that draw visitors to the community. The Ice Festival in January features ice carvings and chili-tasting competitions, while Strawberry Fest in June highlights foods made from strawberries. Apple Fest in September showcases home-baked goods and arts and crafts. Tourism is further supported by the Little River Railroad, which offers rides behind a 1911-built steam locomotive departing from the historic 1883 depot. The city also contains boutique shops and events that contribute to its quaint community appeal.

As of the 2020 census, Coldwater had a population of 13,822. The city is accessible via Interstate 69 and Business Loop I-69, with Memorial Airport serving general aviation needs. Public bus transportation is provided by the Branch Area Transit Authority. Under the Köppen climate classification, Coldwater has a humid continental climate with average January maximums of 30.9 °F and July maximums of 81.9 °F. Annual precipitation averages 39.12 inches, with snowfall averaging 42.7 inches annually.