Colo is a city in Story County, Iowa, United States. The population was 845 at the 2020 census. The Lincoln Highway and Jefferson Highway both pass through Colo. It is part of the Ames, Iowa Metropolitan Statistical Area, which is a part of the larger Ames-Boone, Iowa Combined Statistical Area.

Story County is a county in the U.S. state of Iowa. As of the 2020 census, the population was 98,537, making it the ninth-most populous county in Iowa. The county seat is Nevada; the largest city is Ames. The geographical center of Iowa lies in Story County, 5 miles (8.0 km) northeast of Ames.