La Porte City is a city in Black Hawk County, Iowa, United States. The population was 2,284 at the 2020 census. It is part of the Waterloo–C…La Porte City is a city in Black Hawk County, Iowa, United States. The population was 2,284 at the 2020 census. It is part of the Waterloo–Cedar Falls Metropolitan Statistical Area. La Porte City was platted in 1855. It is named after La Porte, Indiana, the former home of one of its founders.