The Distinguished Service Cross (DSC) is a third-level military decoration awarded to officers; and, since 1993, ratings and other ranks of the British Armed Forces, Royal Fleet Auxiliary and the British Merchant Navy have been included. Additionally, the award was formerly awarded to members of other Commonwealth countries.

The British Merchant Navy is the collective name given to British civilian ships and their associated crews, including officers and ratings. In the UK, it is simply referred to as the Merchant Navy or MN. Merchant Navy vessels fly the Red Ensign and the ships and crew are regulated by the Maritime and Coastguard Agency (MCA), a specialist agency of the UK Department of Transport. British merchant ships are registered under the UK or Red Ensign group ship registries. British Merchant Navy deck officers and ratings are certificated and trained according to STCW Convention and the syllabus of the Merchant Navy Training Board in maritime colleges and other training institutes around the UK.