D1

D1, D01, D.I, D.1 or D-1 can refer to:

Biochemistry and medicine

 * ATC code D01 Antifungals for dermatological use, a subgroup of the Anatomical Therapeutic Chemical Classification System
 * Dopamine receptor D1, a protein
 * Haplogroup D1 (Y-DNA)
 * Vitamin D1, a form of Vitamin D
 * DI, Iodothyronine deiodinase type I, an enzyme involved with thyroid hormones

Technology

 * Nikon D1, a digital single-lens reflex camera
 * D1, former brand of T-Mobile in Germany
 * D1, an abbreviation for DOCSIS 1.0 1.0, an international telecommunications standard
 * D-1 (Sony), an early digital video recording format
 * STS-61-A, also known as D-1, the 22nd mission of NASA's Space Shuttle program
 * D-1, from the Proton (rocket family), Russian rockets
 * Mercedes D.I, a 1913 German aircraft engine

World War I fighter aircraft

 * AEG D.I
 * Albatros D.I
 * Halberstadt D.I, experimental version of Halberstadt D.II (and Aviatik D.I variant)
 * Aviatik (Berg) D.I
 * Daimler D.I
 * Deutsche Flugzeug-Werke D.I
 * Euler D.I
 * Flugzeugbau Friedrichshafen D.I
 * Fokker D.I
 * Hansa-Brandenburg D.I
 * Junkers D.I
 * Knoller D.I, an Imperial and Royal Aviation Troops aircraft
 * Phönix D.I
 * Schütte-Lanz D.I
 * Siemens-Schuckert D.I
 * WKF D.I, an Imperial and Royal Aviation Troops aircraft

Other uses in military

 * Char D1, a 1930s French tank
 * Dewoitine D.1, a 1920s French single-seat fighter aircraft
 * Dunne D.1, a 1907 British experimental aircraft
 * 152 mm howitzer M1943 (D-1), a Soviet World War II artillery system
 * HMS D1, British early 20th century submarine
 * USS D-1 (SS-17), a 1909 American submarine

Locomotives and trams

 * D1-class, a variant of D-class Melbourne tram
 * D1 multiple unit, a train built in 1960s-1980s in Hungary for Soviet railways
 * LB&SCR D1 class, an 1873 British tank locomotive
 * NCC Class D1, a Northern Counties Committee Irish gauge steam locomotive
 * Pennsylvania Railroad class D1, an 1868 American steam locomotive
 * Bavarian D I, an 1871 Bavarian tank locomotive
 * Min'an Electric D01, a sports luxury vehicle

Roads

 * D1 road (Croatia)
 * D1 motorway (Czech Republic)
 * D1 motorway (Slovakia)

Other uses in transportation

 * D1, a model of BSA Bantam British motorcycle
 * D1, a commuter rail line of Moscow Central Diameters
 * D1 Denby Darts, a bus service in Yorkshire, UK
 * BYD D1, an electric multi purpose vehicle (MPV)

Sports

 * NCAA Division I, D-I, the highest division of American collegiate athletics
 * D1 Grand Prix, a production car drifting series from Japan
 * D1NZ, a production car drifting series in New Zealand

Other uses

 * D1 (building), a residential building in Dubai
 * D1 (Longs Peak), a technical climbing route in Colorado, U.S.
 * D1, a Dublin postal district
 * D1, a guitar model by C. F. Martin & Company
 * D1, a code in Town and country planning in the United Kingdom
 * D1, a transmittered juvenile female bald eagle from the 2011 clutch of the Decorah Bald Eagles
 * D1, a discount store chain from Colombia.
 * D-1 visa, a non-immigrant U.S. visa
 * "D-1", a song from Yves (single) by Loona
 * D1 Recordings, an Irish independent techno record label
 * D01, ECO code for the Richter-Veresov Attack chess opening
 * Digital One - also known as D1 National, a digital radio multiplex in the United Kingdom
 * Dhoom, a 2004 Indian Hindi-language action film by Sanjay Gadhvi, first part of the Dhoom film series