Christiansted Harbor Seaplane Base (IATA: SSB, FAA LID: VI32), also known as St. Croix Seaplane Base, is located in the harbor by Christiansted, Saint Croix, U.S. Virgin Islands. This private-use airport is owned by the Virgin Islands Port Authority. The sea base is home to Seaborne Airlines U.S. Virgin Islands, the only multi-engine sea plane airline operating in the United States.

As per Federal Aviation Administration records, this seaplane base had 72,632 passenger boardings (enplanements) in calendar year 2004 and 68,386 enplanements in 2005.