Importance. Since the late 1990s, the autonomous parts of the unitary United Kingdom have begun to assert their own interests in the international arena. The foreign relations of Northern Ireland and Wales are interesting not only from the point of view of the theory of paradiplomacy; after the UK's withdrawal from the European Union, Northern Ireland turned out to be a border region, which led to an increase in its international contacts, as well as to changes in its selfrepresentation and London’s policy towards this autonomy. A comparative analysis of the international activities of the two autonomous parts of Great Britain is carried out. Due to the devolution process that has been taking place since the beginning of the 21st century, the authorities of Wales, Northern Ireland and Scotland have gained some rights to manage their territories, and have also begun to develop their external relations. The similarities and differences between the approaches of Northern Ireland and Wales to their international activities are considered. Materials and methods. The source base is provided by the websites of the Northern Ireland and Wales governments, policy documents concerning their external relations, press materials. The research methodology is based on comparative analysis and study of documents. Various theoretical concepts of paradiplomacy and A.S. Kuznetsov’s system of criteria for measuring the international activity of regions are used. Results. It is shown that in their external relations Wales and Northern Ireland set different goals, use different approaches and cooperate with different partners. They also differ in their assessments of the activities of the national foreign policy agencies to protect the interests of the autonomous parts of the United Kingdom. Conclusions. Northern Ireland and Wales share a similar set of competencies, similar interests and opportunities in developing their external relations and a similar set of governmental and nondepartmental instruments for their implementation. Wales' approach can be described as more modern, with its authorities emphasizing the promotion of the region on the world stage through the useof new technologies. At the same time, Wales is more inclined to diversify its international contacts, while Northern Ireland, for natural reasons, gravitates more towards its southern neighbor.