Thessaloniki, also known as Thessalonica, Saloniki, Salonika, or Salonica, is the second-largest city in Greece, with slightly over one million inhabitants in its metropolitan area, and the capital of the geographic region of Macedonia, the administrative region of Central Macedonia and the Decentralized Administration of Macedonia and Thrace. It is also known in Greek as "η Συμπρωτεύουσα", literally "the co-capital", a reference to its historical status as the Συμβασιλεύουσα or "co-reigning" city of the Byzantine Empire alongside Constantinople.

The European Youth Capital is the title awarded by the European Youth Forum to a European city, designed to empower young people, boost youth participation and strengthen European identity through projects focused on youth-related cultural, social, political and economic life and development. The European Youth Capital is an initiative by the European Youth Forum and is awarded for a period of one year. The first capital was chosen in 2009. Since 2014, the Congress of Local and Regional Authorities of the Council of Europe is an official partner the European Youth Capital title. The current, capital for the 2024 calendar year is Ghent, Belgium.