Stockton is a city in Muscatine County, Iowa, United States. The population was 176 at the time of the 2020 census. It is part of the M…Stockton is a city in Muscatine County, Iowa, United States. The population was 176 at the time of the 2020 census. It is part of the Muscatine Micropolitan Statistical Area. Stockton was laid out at the time the railroad was built through it. Stockton was a depot on the Chicago, Rock Island and Pacific Railroad.