The Visegrád Four (V4) is a regional cooperation of four Central European countries: the Czech Republic, Hungary, Poland, and Slovakia, established in 1991. The members of the group signed a declaration in Visegrád (Hungary) on close cooperation towards European integration. Following the accession of the V4 member states to the EU, the group focused on promoting cooperation and stability in the wider Central European region.

A postage stamp designed by the Polish designer Agnieszka Sobczyńska celebrates the 30th anniversary of the close political, economic and social relationship between the members of the Visegrád Group.