The Defence Research Agency (DRA) was an executive agency of the UK Ministry of Defence (MOD) from April 1991 until April 1995. At the time, the DRA was Britain's largest science and technology organisation. In April 1995, the DRA was combined with five other MOD establishments to form the Defence Evaluation and Research Agency.

The DRA was formed on 1 April 1991^[1] as an amalgamation of the following Defence Research Establishments:

• Admiralty Research Establishment (ARE) – major sites Portsdown, Hampshire and Southwell, Dorset ("Maritime Division")^{[citation needed]}
• Royal Aircraft Establishment (RAE) – major site Farnborough, Hampshire ("Aerospace Division")^[2]
• Aeroplane and Armament Experimental Establishment (A&AEE) – major site Boscombe Down^{[citation needed]}
• Royal Armament Research and Development Establishment (RARDE) – major site Fort Halstead, Kent ("Military Division")^{[citation needed]}
• Royal Signals and Radar Establishment (RSRE) – major site Malvern, Worcestershire ("Electronics Division")^{[citation needed]}

DRA's headquarters was created at the RAE site at Farnborough, but the other major sites maintained a great deal of independence.^{[citation needed]}

DRA's first Chief Executive was Nigel Hughes, followed by John Chisholm who took over in August 1991.^{[citation needed]}

In April 1995, the DRA was combined with five other MOD establishments to form the Defence Evaluation and Research Agency (DERA), DRA's John Chisholm becoming Chief Executive of the enlarged DERA (split in July 2001 into DSTL and QinetiQ).^{[citation needed]}