Lisbon is a city in Linn County, Iowa, United States, adjacent to the city of Mount Vernon. The population was 2,233 at the time of the 2020 cen…Lisbon is a city in Linn County, Iowa, United States, adjacent to the city of Mount Vernon. The population was 2,233 at the time of the 2020 census. It is part of the Cedar Rapids metropolitan area. Lisbon was laid out in 1851. It was named after Lisbon, the capital of Portugal.