Winfield is a city in Henry County, Iowa, United States. The population was 1,033 at the time of the 2020 census. Winfield was laid out in 1852. It experienced a growth with the arrival of the Burlington and Northwestern Railway in late 1876, connecting the town with Burlington. The line was extended along the east side of town and reached Washington at the start of 1880, and in 1881, the Burlington and Western Railway was incorporated to build a line from Winfield to Oskaloosa. The new line branched from the Burlington and Northwestern just north of town reached Coppock the spring of 1882 and Oskaloosa in late 1883. These were 3 ft gauge railways.