Eurovision Song Contest 1966

The Eurovision Song Contest 1966 was the 11th edition of the Eurovision Song Contest. It took place in Luxembourg City, Luxembourg, following the country's victory at the 1965 contest with the song "Poupée de cire, poupée de son" by France Gall. Organised by the European Broadcasting Union (EBU) and host broadcaster Compagnie Luxembourgeoise de Télédiffusion (CLT), the contest was held at the Villa Louvigny on 5 March 1966 and was hosted by Luxembourgish television presenter Josiane Chen.

Eighteen countries participated in the contest, the same that had competed the year before.

The winner was Austria with the song "Merci, Chérie", performed and composed by Udo Jürgens, and written by Jürgens and Thomas Hörbiger. This was Udo Jürgens third consecutive entry in the contest, finally managing to score a victory for his native country. Austria would not go on to win again until the 2014 edition. This was also the first winning song to be performed in German. The contest is also noted for its historic results for several countries. Austria who came first, Sweden who came second, Norway who came third and Belgium who came fourth all achieved their best results up until then, some of which would stand for several decades. In contrast, traditional Eurovision heavyweights such as France, United Kingdom, and Italy all achieved their worst result by far up till that point, with the general public in the aforementioned countries meeting these results with a degree of consternation.

The rule stating that a country could only sing in any of its national languages was created this year, possibly due to the 1965 Swedish entry which was sung in English.