The Parti des déshérités de Madagascar (PADESM, "Party of the Disinherited of Madagascar") was a political party active in Madagascar from June 1946 into the First Republic (1960–1972). It was formed in reaction to the establishment and rapid political success of the Mouvement démocratique de la rénovation malgache (MDRM) political party, formed by Merina elites on a platform of independence from France. While nationalism - and therefore the MDRM - had widespread support from all ethnic communities, PADESM championed the empowerment and equitable government of coastal peoples, who had historically been subjugated by the Merina and feared the MDRM could ensure their return to political dominance upon independence. They actively recruited and campaigned along ethnic lines, initially including coastal peoples and the descendents of Merina slaves, but eventually excluding the latter entirely. The formation and political success of PADESM was actively fostered by the French colonial administration, which manipulated election results in favor of the coastal party.
The nationalist Malagasy Uprising of 1947 led the French colonial administration to dissolve the MDRM and temporarily suspend all other political parties, including PADESM. Tensions between the parties played out during the uprising through targeted acts of violence between supporters of the rival groups. An estimated 1,900 to 5,000 PADESM supporters were killed during the uprising by pro-MDRM nationalist fighters. After the nationalist movement was crushed in December 1948, PADESM experienced an increase in popularity, aided by continuing French support. The party won several key political elections in the 1950s. Nevertheless, as the process toward independence began, it became fragmented between conservative and progressive factions, with the latter splitting off in December 1956 to form the Parti sociale démocrate (PSD, Social Democratic Party). With this split and independence in 1960, PADESM became moribund.
PADESM has had a lasting impact on political life in Madagascar. Philibert Tsiranana, leader of the PSD, went on to become Madagascar's first president upon independence in 1960. Many other major political figures in Madagascar have connections to PADESM and PSD, including former president Didier Ratsiraka and former prime minister Jacques Sylla. More broadly, the formation of PADESM cemented ethnic rivalries within Malagasy politics, linking the interests of specific ethnic groups with particular political parties.