Basque nationalism (Basque: eusko abertzaletasuna [eus̺ko abeɾts̻aletas̺una]; Spanish: nacionalismo vasco; French: nationalisme basque) is a form of nationalism that asserts that Basques, an ethnic group indigenous to the western Pyrenees, are a nation and promotes the political unity of the Basques, today scattered between Spain and France. Since its inception in the late 19th century, Basque nationalism has included separatist movements.

Basque nationalism, spanning three different regions in two states (the Basque Autonomous Community and Navarre in Spain, and the French Basque Country in France) is "irredentist in nature" as it favours political unification of all the Basque-speaking provinces.