D20

D20, D-20 or d20 may refer to:

Arts, entertainment, and media

 * d20, a polyhedral die commonly used in role-playing games
 * d20 System, a role-playing game system published by Wizards of the Coast
 * Arriflex D-20, a film-style digital high definition movie camera
 * D-20, a version of the Roland D-50 synthesizer
 * Dimension 20, a tabletop role-playing game show made by CollegeHumor/Dropout
 * Queen's Gambit Accepted, Encyclopaedia of Chess Openings code

Military

 * 152 mm gun-howitzer D-20, a Soviet artillery piece
 * ARA Almirante Brown, a destroyer that served with the Argentine Navy between 1961 and 1982
 * BRAZILIAN DESTROYER ESCORT Baependi, a destroyer escort that served with the Brazilian Navy between 1944 and 1975
 * GREEK DESTROYER Doxa, a destroyer that served with the Royal Hellenic Navy between 1951 and 1972
 * HMS Fife (D20), a Royal Navy guided missile destroyer launched in 1964 and decommissioned in 1987

Science

 * D20, a diffractometer located at Institut Laue–Langevin used in neutron research
 * Heavy water, or deuterium oxide (D2O or 2H2O)

Vehicles and transport

 * D20 road (Croatia), a state road
 * Aero Synergie Jodel D20, a French ultralight
 * Chevrolet D-20, a pick-up truck made in Brazil and Argentina
 * LNER D20, a class of British steam locomotives
 * Senova D20, a subcompact car made by SAIC in China
 * Soloviev D-20, a Soviet turbofan engine

Other

 * Dublin 20, a Dublin, Ireland postal district
 * 2020 Democratic National Convention, American political convention, branded as "D20"