Defence Intelligence (DI) is a member of the United Kingdom Intelligence Community, but differs from the agencies (SIS, GCHQ, and the Security Service) in that it is not a stand-alone organisation, but is an integral part of the Ministry of Defence (MOD). The organisation employs a mixture of civilian and military staff and is funded within the Defence budget. Like the rest of the MOD, Defence Intelligence was subject to the 2008 'Streamlining' initiative in which 20–25 percent of Central London staff were cut and it has had to continue to find additional savings since. The organisation was formerly known as the Defence Intelligence Staff or DIS, but changed its name in 2009.

Military intelligence is a military discipline that exploits a number of information collection and analysis approaches to provide guidance and direction to commanders in support of their decisions. This is achieved by providing an assessment of available data from a wide range of sources, directed towards the commanders' mission requirements or responding to focused questions as part of the operational or campaign planning activity. In order to provide an informed analysis, the commander's information requirements are first identified. These information requirements are then incorporated into a process of intelligence collection, analysis and dissemination.