The European Border and Coast Guard Agency, commonly known as Frontex, is an agency of the European Union headquartered in Warsaw, Poland. In coordination with the border and coast guards of member states, it exercises border control of the European Schengen Area, a task within the area of freedom, security and justice domain. Formally, the Agency's remit is to "support Member States on the ground in their efforts to protect the external borders"; it does not have authority to act otherwise unless "external border control" [by a member state] "is rendered ineffective to such an extent that it risks jeopardising the functioning of the Schengen area".

Border control comprises measures taken by governments to monitor and regulate the movement of people, animals, and goods across land, air, and maritime borders. While border control is typically associated with international borders, it also encompasses controls imposed on internal borders within a single state.