Cresco is a city in Howard County, Iowa, United States. The population was 3,868 in the 2010 census, a decline from 3,905 in 2000 census. It is the county seat of Howard County. Cresco is home to one of the largest school districts in Iowa in terms of square miles, the Howard-Winneshiek Community School District. The high school is called Crestwood High School. Crestwood Elementary/Junior High School are also in Cresco.