D34

D34 may refer to:


 * Akaflieg Darmstadt D-34, a German sailplane
 * BHP Port Kembla D34 class, a class of diesel locomotives
 * BRAZILIAN DESTROYER Mato Grosso, a Mato Grosso-class destroyer of the Brazilian Navy
 * D34 road (Croatia)
 * HMS Diamond (D34), a D-class destroyer of the Royal Navy
 * HMS Velox (D34), a V-class destroyer of the Royal Navy
 * LNER Class D34, a class of British steam locomotives
 * Tarrasch Defense, a chess opening
 * d34, a die with 34 sides