Mount Vernon is a city in Linn County, Iowa, United States, adjacent to the city of Lisbon. The population was 4,527 at the time of the 2020 census. Mount Vernon is part of the Cedar Rapids Metropolitan Statistical Area.

Linn County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 230,299, making it the second-most populous county in Iowa. The county seat is Cedar Rapids. Linn County is named in honor of Senator Lewis F. Linn of Missouri. Linn County is included in the Cedar Rapids, IA Metropolitan Statistical Area.