This article investigates the uses of the term “Hungarian Empire” during the long nineteenth century. It argues that the term “empire” emerged in the Hungarian political discourse in the Vormärz era and it was used to denote the imagined integrity of Hungary proper, Transylvania, Croatia, Slavonia, and eventually Dalmatia on the grounds of the historic rights of the Holy Crown of Hungary in the form of a composite nation-state. This usage of the term became ubiquitous after the Austro-Hungarian Compromise. A second meaning pertaining to imperialist foreign policy entered the dictionary of Hungarian political discourse in the late nineteenth century. Fed by the recently created memory of the medieval Hungarian great power, several pressure groups in fin-de-siècle Hungary lobbied for a Hungarian (informal) empire in Southeastern Europe and beyond. While several lobby groups were firmly embedded in the framework of the Austro-Hungarian monarchy, some of these visionaries imagined a Hungarian empire independent from the Habsburg structures. A short comparison with the Croatian and Czech political discourses illuminates that the first meaning of empire (composite nation-state) did not differ in substance from contemporary terminology in other Habsburg lands but the second meaning (imperialism) was indeed a unique phenomenon in the Habsburg monarchy.