D43, D-43 or D.43 may refer to :

• HMS Coventry (D43), a 1917 British Royal Navy C-class light cruiser
• HMS Matapan (D43), a 1945 British Royal Navy Battle-class fleet destroyer
• D43 road (Croatia), a state road

and also:

• the ICD-10 code for a neoplasm of uncertain or unknown behaviour of brain and central nervous system
• Semi-Slav Defense chess code

• Lowell Walter Residence
• Lowell, Washington
• Lowell, West Virginia
• Lowell Wood
• Lowell W. Paxson
• Lowe Marlburian
• Lowe Mill
• Low emission buses in London
• Low emissions locomotives
• Low emissions zone
• Low Emission Zone
• Low emission zone
• Low-emissivity
• Lowen
• Lowenberger Land
• Lowenberg's sign
• LO Wenckebach
• L O Wenckebach
• Lowendal
• Lowender peran
• Low Energy Antiproton Ring
• Low energy bulb
• Low-energy collision-induced dissociation
• Low-energy light bulb
• Low-energy nuclear reaction