The "cursed soldiers" (also known as "doomed soldiers", "accursed soldiers" or "damned soldiers"; Polish: żołnierze wyklęci) or "indomitable soldiers" (Polish: żołnierze niezłomni) is a term applied to a variety of anti-Soviet imperialist and anti-communist Polish resistance movements formed in the later stages of World War II and its aftermath by members of the Polish Underground State. This all-encompassing term for a widely heterogeneous movement was introduced in the early 1990s.

The clandestine organisations continued their armed struggle against the communist regime of Poland well into the 1950s. The guerrilla warfare included an array of military attacks launched against the regime's prisons and state security offices, detention facilities for political prisoners, and concentration camps that were set up across the country. Most of the Polish anti-communist groups ceased to exist in the late 1950s, as they were hunted down by agents of the Ministry of Public Security and Soviet NKVD. The last known "cursed soldier", Józef Franczak, was killed in an ambush in 1963.

The best-known Polish anti-communist resistance organisations operating in Stalinist Poland included Freedom and Independence (Wolność i Niezawisłość, WIN), National Armed Forces (Narodowe Siły Zbrojne, NSZ), National Military Union (Narodowe Zjednoczenie Wojskowe, NZW), Konspiracyjne Wojsko Polskie (Underground Polish Army, KWP), Ruch Oporu Armii Krajowej (Home Army Resistance, ROAK), Armia Krajowa Obywatelska (Citizens' Home Army, AKO), NIE (NO, short for Niepodległość), Armed Forces Delegation for Poland (Delegatura Sił Zbrojnych na Kraj), and Wolność i Sprawiedliwość (Freedom and Justice, WiS).

Similar Eastern European anti-communist insurgencies went on in neighbouring countries.

The operations and history of the "cursed soldiers" have prompted controversy over the degree to which individual fighters or their units were involved in war crimes against Jews and other ethnic minorities on Polish soil and against civilians in general; common responses to the accusations include claiming that they were partially or completely fabricated as part of communist propaganda aimed at discrediting the soldiers, or that any genuine victims were killed due to their involvement in or cooperation with communist authorities and their ethnicity had little or no bearing on their eventual demise.