DMS Maritime, formerly Defence Maritime Services, is a company providing port services to the Australian Defence Force and Marine Unit. It is a subsidiary of Serco.

Serco Group plc is a British multinational defence, health, space, justice, migration, customer services, and transport company. It is headquartered in Hook, Hart, England. The company operates in Continental Europe, the Middle East, the Asia Pacific region, including Australia and Hong Kong, and North America. It is listed on the London Stock Exchange and is a constituent of the FTSE 250 Index.