South Wood County Airport (IATA: ISW, ICAO: KISW, FAA LID: ISW), also known as Alexander Field, is a public use airport located one nautical mile (1.85 km) south of the central business district of Wisconsin Rapids, a city in Wood County, Wisconsin, United States.

The airport is owned and operated by the City of Wisconsin Rapids, the Village of Port Edwards, the Town of Grand Rapids and the City of Nekoosa. It is included in the Federal Aviation Administration (FAA) National Plan of Integrated Airport Systems for 2025–2029, in which it is categorized as a local general aviation facility.