Pan-Germanism, also occasionally known as Pan-Germanicism, is a pan-nationalist political idea. Pan-Germanists originally sought to unify all the German-speaking people – and possibly also non-German Germanic-speaking peoples – in a single nation-state known as the Greater Germanic Reich, fully styled the Greater Germanic Reich of the German Nation.

A nation-state is a political unit where the state, a centralized political organization ruling over a population within a territory, and the nation, a community based on a common identity, are congruent. It is a more precise concept than "country", since a country does not need to have a predominant national or ethnic group.