D78

D78 may refer to:


 * D. 78, Aria "Son fra l’onde" for soprano and piano, composed by Franz Schubert in 1813
 * HMS Archer (D78), Long Island-class escort carrier built by the US in 1939–1940, operated by the Royal Navy during World War II
 * HMS Vidette (D78), Admiralty V class destroyer of the Royal Navy
 * HMS Wolverine (D78), Admiralty modified W class destroyer built for the Royal Navy
 * London Underground D78 Stock, type of sub-surface rolling stock which operated on the District line of the London Underground