Mansfield is an unincorporated community in Brown County, South Dakota, United States. Although it is not tracked by the United States Census Bureau, Mansfield has been assigned the ZIP code of 57460. Located just west of highway 281, it is approximately 18 miles south of Aberdeen, the third largest city in South Dakota. The James River Valley near which Mansfield is situated, is some of the richest farmland in the state. Additionally, this area is widely known for its large variety of game and is a popular pheasant hunting venue.