This is a list of irredentist claims or disputes. Irredentism is any political or popular movement that seeks to claim, reclaim and occupy a land that the movement's members consider to be a "lost" (or "unredeemed") territory from their nation's past. Not all territorial disputes are irredentist, although they are often couched in irredentist rhetoric to justify and legitimise such claims both internationally and within the country. What is and is not considered an irredentist claim is sometimes contentious.

Current governmental irredentist claims Argentina

Argentina has claimed land that used to be part of, or was associated with, the Spanish territory of the Viceroyalty of the Rio de la Plata. The viceroyalty began to dissolve into separate independent states in the early 19th century, one of which later became Argentina. The claims included, amongst other areas, parts of what in 2019 were Chile, Paraguay, Brazil, Uruguay, and Bolivia. Some of these claims have been settled, although others are still active. The active claims include part of the land border with Chile, a section of the Antarctic continent, and the British South Atlantic islands, including the Falklands.

Argentina renews these claims periodically. It considers the Falkland archipelago to be part of the Tierra del Fuego Province, along with South Georgia and the South Sandwich Islands. Its claim is included in the transitional provisions of the Constitution of Argentina as amended in 1994:

Bolivia

The 2009 constitution of Bolivia states that the country has an "unrenounceable right over the territory that gives it access to the Pacific Ocean and its maritime space".CAPÍTULO CUARTO, REIVINDICACIÓN MARÍTIMA. Artículo 267. I. El Estado boliviano declara su derecho irrenunciable e imprescriptible sobre el territorio que le dé acceso al océano Pacífico y su espacio marítimo. II. La solución efectiva al diferendo marítimo a través de medios pacíficos y el ejercicio pleno de la soberanía sobre dicho territorio constituyen objetivos permanentes e irrenunciables del Estado boliviano.Constitution of Bolivia Bolivia and Peru ceded land to Chile after the War of the Pacific, which left Bolivia as a landlocked country. The lost Atacama region is a source of conflict in the two countries' relations. Every year, Bolivians celebrate the Día del Mar (Day of the Sea) in observance of the lost territories.

China (PRC)

The preamble to the Constitution of China states, "Taiwan is part of the sacred territory of the People's Republic of China (PRC). It is the lofty duty of the entire Chinese people, including our compatriots in Taiwan, to accomplish the great task of reunifying the motherland." The PRC's claim to sovereignty over Taiwan is generally based on the theory of the succession of states, with the PRC claiming that it is the successor state to the Republic of China (ROC).

However, the People's Republic of China (PRC) has never controlled Taiwan. The ROC government formerly administered both mainland China and Taiwan but has been administering primarily Taiwan only, since the Chinese Civil War in which it fought the People's Liberation Army of the Chinese Communist Party. While the official name of the state remains the 'Republic of China', the country is commonly called 'Taiwan', as Taiwan makes up 99% of the controlled territory of the ROC.

China (ROC)

The Qing dynasty of China ceded Taiwan and the Penghu Islands to the Empire of Japan in perpetuity in the Treaty of Shimonoseki in 1895, along with the Liaodong Peninsula. The Republic of Formosa was a short-lived republic that then existed on the island of Taiwan for about five months in 1895 in the period between the formal cession of Taiwan to the Empire of Japan and de facto Japanese occupation and control. Japan then established a colony on Taiwan that existed until control of Taiwan was ceded to the Nationalist Government of the Republic of China in 1945.

Article 4 of the Constitution of the Republic of China originally stated that "[t]he territory of the Republic of China within its existing national boundaries shall not be altered except by a resolution of the National Assembly". The National Assembly was de facto abolished in 2005, whose power was inherited by the Legislative Yuan. The Legislative Yuan holds the power to decide a referendum regarding changes to the ROC territory. Throughout the 1950s and 1960s, the Government of the Republic of China on Taiwan actively maintained itself to be the legitimate ruler of the entirety of China, including both mainland China, Taiwan, Tibet and Outer Mongolia. As part of its current policy of maintaining the 'status quo', the ROC has not renounced claims over the territories currently controlled by the PRC, Mongolia, India, Russia, Myanmar, Pakistan, Bhutan, North Korea and some Central Asian states. However, the ROC does not actively pursue these claims in practice; the remaining claims that the ROC is actively seeking are of uninhabited islands: the Senkaku Islands, whose sovereignty is also asserted by Japan and is part of Ishigaki, Okinawa. As far as the Paracel Islands and Spratly Islands in the South China Sea are concerned, the Philippines, Malaysia, Brunei, and Vietnam have repeatedly claimed sovereignty over some or most of these islands, rejecting the Chinese claimed "Nine-dash line".

Comoros Article 1 of the Constitution of the Union of the Comoros begins: "The Union of the Comoros is a republic, composed of the autonomous islands of Mohéli, Mayotte, Anjouan, and Grande Comore." Mayotte, geographically a part of the Comoro Islands, was the only island of the four to vote against independence from France (independence losing 37%–63%) in the referendum held 22 December 1974. Mayotte is currently a department of the French Republic.UN General Assembly, Forty-ninth session: Agenda item 36 Security Council S/PV. 1888 para 247 S/11967

Guatemala

Guatemala has claimed Belize in whole or in part since 1821.

Mauritius

In 1810, the British captured the Ile de France and renamed it Mauritius. By the Treaty of Paris of 30 May 1814, France ceded the Ile de France and all its dependencies (including the Chagos Archipelago) to the United Kingdom.

The Constitution of Mauritius states that the Outer islands of Mauritius includes the islands of Mauritius, Rodrigues, Agaléga, Cargados Carajos and the Chagos Archipelago, including Diego Garcia and any other island comprised in the State of Mauritius. The Government of the Republic of Mauritius has stated that it does not recognise the British Indian Ocean Territory (BIOT) which the United Kingdom created by excising the Chagos Archipelago from the territory of Mauritius prior to its independence, and claims that the Chagos Archipelago including Diego Garcia forms an integral part of the territory of Mauritius under both Mauritian law and international law.

Mauritius has claimed sovereignty over the Chagos Archipelago from Great Britain since 1968, but in 2025, Great Britain yielded to pressure from Mauritius, returning the Chagos Archipelago to the state of Mauritius.

India, Pakistan and China

Kashmir, a mountainous region spanning the northernmost tip of the Indian subcontinent, has been the subject of a territorial dispute between India and Pakistan since the partition of India in August 1947. In the face of a Pakistani invasion, the Kashmiri king Hari Singh signed the Instrument of Accession with India, bringing the country into a direct state of conflict with Pakistan in what would become the Indo-Pakistani War of 1947–1948. Since then, the two countries have fought multiple wars over the issue, but neither side has managed to capture and control the entire region. China became involved in the conflict in 1962, after consolidating control over what had been Indian-administered territory in Kashmir during the Sino-Indian War.

In practice, the zones of control in Kashmir remain divided into three disputed parts, with India and Pakistan separated by the Line of Control and India and China separated by the Line of Actual Control. India claims the entire region on the basis of the Instrument of Accession signed with Kashmir's king in 1947; Pakistan claims only the Indian-controlled parts of Kashmir, having signed the Sino-Pakistan Agreement in 1963; and China's claims are limited to parts of Indian-controlled territory, not including areas claimed by Pakistan. Official government maps of these countries generally reflect these territorial claims by including the disputed lands within their borders.

Israel and Palestine

In November 1947, the United Nations Partition Plan for Palestine was adopted with 72% in-favour votes, aiming to split the territory of the region into a Jewish state and an Arab state. However, this plan was never implemented—the Israeli Declaration of Independence had been rejected by the Arab League and ultimately led to the 1948 Palestine war. This war led to the emergence of three zones of control: Israel, an independent Jewish state; the West Bank, annexed by Jordan; and the Gaza Strip, occupied by Egypt. Israel's founding ideology, the Zionist movement, had claimed the territory as the Jewish homeland; these claims are based on the Jews' ancestral habitation and periodic sovereignty in the land as well as the cultural/religious significance of that region as expressed in the Hebrew Bible. The latter is particularly relevant to the Israeli claim to Jerusalem—Israel controlled only half of the city (West Jerusalem) after its independence, with the other half (East Jerusalem) coming under Jordanian control.

In a historical or religious context, many Jews commonly refer to the West Bank as Judea and Samaria (the biblical terms), which formed a large part of the ancient Kingdom of Israel. Following the outbreak of the Six-Day War in 1967, Israel captured the Jordanian-annexed West Bank and the Egyptian-occupied Gaza Strip, in addition to the Syrian Golan Heights and the Egyptian Sinai Peninsula. Since 1967, Israeli settlements have been established throughout these Israeli-occupied territories, which are regarded as having historical and religious significance to the Jewish people and strategic significance to the Israeli state. Israel withdrew from Gaza in 2005, but the Israeli occupation of the West Bank continues, though the Israeli government has never explicitly claimed sovereignty over any part of that territory apart from East Jerusalem, which it effectively annexed in 1967. The Israeli settlements in the West Bank and the Golan Heights, which were unilaterally annexed by Israel in 1981, are usually supported by the Israeli government and protected by the Israeli military, drawing condemnation from the international community as an obstacle to the Israeli–Palestinian peace process. Though the Gazan Israeli settlements were dismantled in 2005, Israel is still regarded as an occupying power over the Gaza Strip under international law and will remain accountable for the territory until the Egyptian–Israeli blockade of Gaza is lifted.