D'addario or Daddario is a surname and may refer to:

• Alessandro D'Addario (born 1997), Sammarinese footballer
• Brian and Michael D'Addario, American musicians in The Lemon Twigs
• Emilio Q. Daddario (1918–2010), American politician, father of Richard, grandfather of Alexandra
  • Alexandra Daddario (born 1986), American actress and model
  • Matthew Daddario (born 1987), American actor, brother of Alexandra
• Gary D'Addario, American retired police commander, television technical advisor and actor
• Lorenzo D'Addario (born 1964), Italian general
• Ray D'Addario (1920–2011), American photographer
• D'Addario, a manufacturer of musical instrument strings and accessories

• Addario