The Union of European Football Associations (UEFA /juːˈeɪfə/ yoo-AY-fə; French: Union des associations européennes de football; German: Union der europäischen Fußballverbände) is one of six continental bodies of governance in association football. It governs football, futsal and beach football in Europe and the transcontinental countries of Turkey, Azerbaijan, Georgia and Kazakhstan, as well as the West Asian countries of Cyprus, Armenia and Israel. UEFA consists of 55 national association members. Since 2022, due to the Russian invasion of Ukraine, FIFA and UEFA suspended all Russian national teams and clubs from any FIFA and UEFA competitions. UEFA consists of the national football associations of Europe, and runs national and club competitions including the European Championship, Nations League, Champions League, Europa League, Conference League, and Super Cup, and also controls the prize money, regulations, as well as media rights to those competitions.

Henri Delaunay acted as the first general secretary and Ebbe Schwartz as the first president. The current president is Aleksander Čeferin, a former Football Association of Slovenia president, who was elected as UEFA's seventh president at the 12th Extraordinary UEFA Congress in Athens in September 2016, and automatically became a vice-president of the world body FIFA.

UEFA was officially inaugurated on 15 June 1954 in Basel, Switzerland, after consultation between the Italian, French, and Belgian associations. At the founding meeting, 25 members were present. However, six other associations which were not present were still recognised as founding members, bringing the total of founding associations to 31. UEFA grew to more than 50 members by the mid-1990s, as new associations were born out of the fragmentation of the Soviet Union, Yugoslavia and Czechoslovakia into their constituent states. UEFA's main headquarters after its foundation were located in Paris, but moved to Bern in 1960. Finally, they moved to Nyon, Switzerland, in 1995, opening the organisation's current headquarters in 1999.

UEFA membership coincides for the most part with recognition as a sovereign country in Europe (48 out of 55 members are sovereign UN member states), although there are some exceptions. One UN member state (Monaco) and one UN General Assembly non-member observer state (Vatican City) are not members. Some UEFA members are not sovereign states, but form part of a larger recognised sovereign state in the context of international law. These include England, Northern Ireland, Scotland and Wales (UK constituent countries), Gibraltar (UK overseas territory), Faroe Islands (Danish Realm), and Kosovo (state with limited recognition), however, in the context of these countries, government functions concerning sport tend to be carried at the territorial level coterminous with the UEFA member entity. UEFA have previously declined membership to those deemed as non-sovereign countries like Jersey.

Some UEFA members are transcontinental states (Azerbaijan, Georgia, Kazakhstan and Turkey) and others are considered part of Europe both culturally and politically (Turkey, Cyprus and Armenia). Countries which had been members of the Asian Football Confederation (AFC) were also admitted to the European football association, such as Israel (because it had been banned from the AFC group in 1974) and Kazakhstan. Involving clubs, some UEFA member associations allow teams from outside their association's main territory to take part in their "domestic" competition, for example, AS Monaco in the French League, various Welsh clubs in the English leagues, or Derry City, situated in Northern Ireland, plays in the Republic of Ireland-based League of Ireland.

On 28 February 2022, due to the 2022 Russian invasion of Ukraine and in accordance with a recommendation by the International Olympic Committee (IOC), the UEFA suspended the participation of Russia. The Russian Football Union unsuccessfully appealed the UEFA ban to the Court of Arbitration for Sport, which upheld the ban. On 26 September 2023 the ban was lifted for the Russia U-17 team enabling them to complete in the 2024 Euro U-17 with UEFA saying "by banning children from our competitions, we not only fail to recognise and uphold a fundamental right for their holistic development but we directly discriminate against them". The lifting of the ban also applied to all teams, men and women, of underage players. This was rejected by the FA of Ukraine, England, and Sweden, with all three threatening to boycott matches against Russia.

Five of the UEFA national teams, Germany, Italy, France, England and Spain, have won 12 out of 22 FIFA World Cups for Europe. These five nations also make up the so-called "Europe's Big Five", consisting of Spain's La Liga, England's Premier League, Germany's Bundesliga, Italy's Serie A and France's Ligue 1.

UEFA executive committee is composed of;