D11, D.XI, D XI or D-11 may refer to:
Ships ARA La Argentina (D-11), a 1981 destroyer of the Argentine navy HMAS Vampire (D11), a 1956 destroyer of the Royal Australian Navy HMS Impulsive (D11), a 1937 United Kingdom Royal Navy destroyer which saw service during World War II Nueva Esparta, a Venezuelan Navy Nueva Esparta-class destroyer
Aircraft Albatros D.XI, a 1918 German single-seat fighter biplane Fokker D.XI, a 1923 Dutch single-seat fighter aircraft Jodel D.11, a two-seat French commercial aircraft
Locomotives Bavarian D XI, an 1895 German saturated steam locomotive model GS&WR Class D11, a steam locomotive of Ireland LNER Class D11, a class of British 4-4-0 locomotives introduced in 1919 by the Great Central Railway
Medicine ATC code D11, Other dermatological preparations, a subgroup of the Anatomical Therapeutic Chemical Classification System Warthin's tumor, ICD-10 code
Other uses DXi, DirectX Instrument plugins D11 motorway (Czech Republic) DirecTV-11, a DirecTV satellite Dublin 11, a Dublin, Ireland postal district Slav Defence, 3.Nf3, Encyclopaedia of Chess Openings code District 11 Caterpillar D11, a large conventional bulldozer London's Metropolitan Police Specialist Firearms Command, formerly known as D11 HDCAM (D-11), a professional digital high definition video format
See also 11D (disambiguation)