Modernist architecture of Kaunas, also known as interwar architecture of Kaunas or Kaunas modernism, is an architectural style that emerged in the interwar period of the Republic of Lithuania. It represents a Lithuanian branch of modernist architecture, which was widespread in many Western countries during the interwar period. The style was formed in Kaunas, the temporary capital of Lithuania at the time, and later spread to other cities of the First Republic of Lithuania. Buildings in this style can also be found in Klaipėda, Palanga, Šiauliai, Birštonas, Jonava, Pasvalys, and Ukmergė, where Kaunas architectural projects were often copied in full. Between 1919 and 1940, approximately 12,000 buildings in this style were constructed in Kaunas.
Notable examples of Kaunas modernism include the Kaunas Garrison Officers' Club Building, the Kaunas Central Post Office, the Church of the Resurrection of Christ, the Vytautas the Great War Museum, among others.