The 190th Fighter Squadron, Blues and Royals friendly fire incident was a friendly fire incident involving two United States Air Force (USAF) Air National Guard 190th Fighter Squadron A-10, and vehicles from the United Kingdom's D Squadron, The Blues and Royals of the Household Cavalry, and took place on 28 March 2003 during the invasion of Iraq by armed forces of the United States and United Kingdom. In the incident, the two USAF A-10s fired on and destroyed two Blues and Royals armored vehicles, killing one British soldier, and wounding five others.

Although not the only fratricide incident during the invasion, the circumstances of the inquest into the death of British lance-corporal of horse Matty Hull and the subsequent verdict of unlawful killing led to much media scrutiny in the UK. This was related to the release of video evidence from the attacking aircraft, and perceived levels of cooperation by government agencies of both the United States and United Kingdom with the British inquest.



In military terminology, friendly fire or fratricide is an attack by belligerent or neutral forces on friendly troops while attempting to attack enemy/hostile targets. Examples include misidentifying the target as hostile, cross-fire while engaging an enemy, long range ranging errors or inaccuracy. Accidental fire not intended to attack enemy/hostile targets, and deliberate firing on one's own troops for disciplinary reasons, is not called friendly fire, and neither is unintentional harm to civilian or neutral targets, which is sometimes referred to as collateral damage. Training accidents and bloodless incidents also do not qualify as friendly fire in terms of casualty reporting.Use of the term "friendly" in a military context for allied personnel started during the First World War, often when shells fell short of the targeted enemy. The term friendly fire was originally adopted by the United States military; S.L.A. Marshall used the term in Men Against Fire in 1947. Many North Atlantic Treaty Organization (NATO) militaries refer to these incidents as blue on blue, which derives from military exercises where NATO forces were identified by blue pennants and units representing Warsaw Pact forces by red pennants. In classical forms of warfare where hand-to-hand combat dominated, death from a "friendly" was rare, but in industrialized warfare, deaths from friendly fire are common.