Operation Hydra was an attack by RAF Bomber Command on a German scientific research centre at Peenemünde on the night of 17/18 August 1943. Group Captain John Searby, commanding officer of No. 83 Squadron RAF, commanded the operation, the first time that Bomber Command used a master bomber to direct the attack of the main force. Hydra was the first operation against the German V-weapon programme, a campaign later known as "Crossbow". The British lost 40 bombers and 215 aircrew, and several hundred enslaved workers in the nearby Trassenheide forced labour camp were killed. The Luftwaffe lost twelve night-fighters and about 170 German civilian personnel were killed, including two V-2 rocket scientists. Assessments of the raids effectiveness vary; the United States Strategic Bombing Survey (1945) called the raid "not effective", while in 1943, Joseph Goebbels wrote of a delay in the programme of six to eight weeks.

Peenemünde is a municipality on the Baltic Sea island of Usedom in the Vorpommern-Greifswald district in Mecklenburg-Vorpommern, Germany. It is part of the Amt of Usedom-Nord. The community is known for the Peenemünde Army Research Center, where the world's first functional large-scale liquid-propellant rocket, the V-2, was developed.