"The Forgotten War" (capitalized) most often refers to:

  • Forgotten War (book), a 2013 book about the Australian frontier wars
  • Korean War (in the United States and the United Kingdom)
  • Ifni War (in Spain)

The term forgotten war is also sometimes, though much less commonly and less specifically, used to refer to:

  • Southern theater of the American Revolutionary War
  • Philippine–American War
  • War of 1812 (outside of the United States)
  • First Barbary War and Second Barbary War
  • Campaigns in Finland during World War II (outside of Finland); see Military history of Finland during World War II
  • Forest Brothers resistance in the Soviet-occupied Baltic states
  • Laotian Civil War (outside of Laos)
  • The Burma Campaign of World War II (outside of Burma)
  • Spanish Civil War (outside of Spain)
  • Soviet–Afghan War
  • First Chechen War and Second Chechen War (outside of Chechnya)
  • War in Afghanistan (2001–2021) (outside of Afghanistan)
  • War in Donbas (2014–2022) (outside of Ukraine)