South St. Paul Municipal Airport (ICAO: KSGS, FAA LID: SGS), also known as Richard E. Fleming Field or simply Fleming Field, is a city-owned public-use airport located two miles (3 km) south of the central business district of South St. Paul, a city in Dakota County, Minnesota, United States. It is named for Richard E. Fleming, a United States Marine Corps Naval Aviator during World War II who was posthumously awarded a Medal of Honor. It is the only reliever airport for Minneapolis–St. Paul International Airport that is not operated by the Metropolitan Airports Commission.

Although most U.S. airports use the same three-letter location identifier for the FAA and IATA, South St. Paul Municipal Airport is assigned SGS by the FAA but has no designation from the IATA.

Over the decade of 1950 and 1960 the airport was the main launch center for Winzen Research Inc. One of the most important companies devoted to the construction and operation of stratospheric balloons. The proximity to their headquarters in Minneapolis, made the ideal place for testing of new balloon models, as well as for technological flights and a number of scientific experiments.