The Eurovision Song Contest 1990 was the 35th edition of the Eurovision Song Contest, held on 5 May 1990 at the Vatroslav Lisinski Concert Hall in Zagreb, Yugoslavia, and presented by Oliver Mlakar and Helga Vlahović. It was organised by the European Broadcasting Union (EBU) and host broadcaster Radiotelevizija Zagreb (RTV Zagreb) on behalf of Jugoslavenska radiotelevizija (JRT), who staged the event after winning the 1989 contest for Yugoslavia with the song "Rock Me" by the group Riva. It was the first contest to be held in the Balkans and the only to be held in a socialist state.

Broadcasters from twenty-two countries participated in the contest, with the same countries that had participated in 1989 returning. The 1990 contest was the first to implement an age limit on the competing performers, following criticism of the participation of two child performers in the previous year's event; all artists were now required to reach the age of sixteen within the year of the contest.

The winner was Italy for the second time in its history, with the song "Insieme: 1992", written and performed by Toto Cutugno. France and Ireland shared second place, with Iceland and Spain rounding out the top five countries. France and Spain both placed within the top 5 for the first time in several years, while Iceland recorded its best ever result up to that point.

The 1990 contest took place in Zagreb, Yugoslavia, following the country's victory at the 1989 contest with the song "Rock Me", performed by the group Riva. It was the first time that Yugoslavia had hosted the contest, and marked the first time the contest had been held in the Balkans and the first edition to be held in a socialist state. The chosen venue was the Vatroslav Lisinski Concert Hall (Croatian: Koncertna dvorana Vatroslava Lisinskog), named after the 19th-century Croatian composer Vatroslav Lisinski and whose main hall has an audience capacity of over 1,800. Constructed between 1963 and 1971, the venue underwent significant renovation ahead of hosting the Eurovision Song Contest. "Eurovision night club" was organised in the Ritz night club.

The same twenty-two countries which had participated in 1989 returned for the 1990 contest; this marked the first time since 1972 that no changes to the composition of the competing countries were made compared to the previous event.

Among the competing artists in this year's event was Ketil Stokkan, who had also represented Norway in 1986. Additionally, Kari Kuivalainen, who had represented Finland in 1986, returned as a backing vocalist for the Finnish group Beat [fi], and the Slovene group Pepel in kri [sl] supported Italy's Toto Cutugno as backing vocalists, having previously represented Yugoslavia in 1975.

Many of the competing songs made reference to the changing political and social landscape across the European continent following revolutions in Central and Eastern European countries in 1989 and spoke of the future of the European continent. The Finnish and German entries referenced the increasing freedoms experienced by citizens in countries formerly under repressive regimes, the Austrian and Norwegian entries harked back to the fall of the Berlin Wall six months prior and the opening of frontiers along the Iron Curtain between east and west Europe, while the Italian entry made reference to the planned signing of the Maastricht Treaty in 1992 which would form the European Union and lead to greater European integration. Other social and political messages were also present among the competing entries, including a message for racial harmony from France, an ode to the environment from the United Kingdom, and Belgium's Philippe Lafontaine presenting a love song for his Macedonian wife.

The Eurovision Song Contest 1990 was produced by the Yugoslav public broadcaster Radiotelevizija Zagreb (RTV Zagreb) on behalf of Jugoslavenska radiotelevizija (JRT). Goran Radman served as executive producer, Nenad Puhovski served as director, Zvjezdana Kvočić served as designer, Seadeta Midžić served as musical director, and Igor Kuljerić served as conductor leading an assembled orchestra, with assistance from Stanko Selak [hr]. A separate musical director could be appointed by each participating delegation to lead the orchestra during its country's performance, with the host conductors also available to conduct for those which did not appoint their own conductor. On behalf of the contest organisers, the European Broadcasting Union (EBU), the event was overseen by Frank Naef as scrutineer. Over 400 journalists covered the event. The overall costs to organise the contest was about 6 million Yugoslav dinars.