The South Wind was a named passenger train equipped and operated jointly by the Pennsylvania Railroad, the Louisville and Nashville Railroad, the Atlantic Coast Line Railroad, and the Florida East Coast Railway. The South Wind began operations in December 1940, providing streamliner service between Chicago, Illinois and Miami, Florida. This was one of three new seven-car, all-coach streamliners operating in coordination every third day along different routes between Chicago and Miami. The other two longest enduring Chicago-Florida trains were the City of Miami and the Dixie Flagler. The South Wind remained in service through the creation of Amtrak in 1971.

The Louisville and Nashville Railroad, commonly called the L&N, was a Class I railroad that operated freight and passenger services in the southeast United States.