Donnellson is a city in Lee County, Iowa, United States. The population was 885 at the time of the 2020 census. It is part of the Fort Madison …Donnellson is a city in Lee County, Iowa, United States. The population was 885 at the time of the 2020 census. It is part of the Fort Madison-Keokuk Micropolitan Statistica Area. What would be Donnellson was first surveyed by H. A. Summers for Esten Donnell, for who the town would be named. Esten’s son, W. R. Donnell helped construct the first buildings in Donnellson, and served as the railroad agent and post master. The town would begin to grow after the Chicago, Burlington and Quincy Railroad passed through to town. Donnellson was incorporated on October 25, 1892. At this time Donnellson was around 120 acres and 200 residents.