Seaboard Coast Line Industries, Inc., incorporated in Delaware on May 9, 1969, was a railroad holding company that owned the Seaboard Coast Line Railroad, its subsidiary Louisville and Nashville Railroad, and several smaller carriers. Its railroad subsidiaries were collectively known as the Family Lines System. Its headquarters were in Jacksonville, Florida, in the United States. Through 1979, the Family Lines network totaled 16,326 miles (26,274 km) in 13 states.

The company succeeded SCL Industries, Inc., incorporated August 1, 1968, in Virginia and renamed Seaboard Coast Line Industries, Inc. on February 5, 1969.

On November 1, 1980, Seaboard Coast Line Industries merged with Chessie System, Inc. to form CSX Corporation (Chessie-Seaboard Multiplied), and in 1983 the Family Lines units were combined as the Seaboard System Railroad. In 1986, Seaboard System was renamed CSX Transportation, and then merged with sister CSX Corp. subsidiary Chessie System to form a single new railroad, reporting mark CSXT.