Based in part upon the S.23 Empire flying boat, the flagship of Imperial Airways, the S.25 was extensively re-engineered for military service. It was one of the most powerful and widely used flying boats throughout the Second World War, and was involved in countering the threat posed by German U-boats in the Battle of the Atlantic. RAF Sunderlands also saw service throughout the Korean War and continued in service until 1959. It also took part in the Berlin airlift. Sunderlands remained in service with the Royal New Zealand Air Force (RNZAF) until 1967.
Sunderlands converted for civil use, known as Short Sandringhams, continued in airline operation until 1974. A single airworthy example remains on display in Florida at Fantasy of Flight.