Sweden was represented at the Eurovision Song Contest 1966 with the song "Nygammal vals", composed by Bengt-Arne Wallin, with lyrics by Björn Lindroth, and performed by Lill Lindfors and Svante Thuresson.

The Swedish participating broadcaster, Sveriges Radio (SR), selected its entry through a national final titled Svensk sångfinal.

Sweden scored 16 points and finished in 2nd place at the contest in Luxembourg, its highest ever placement at the time.

Svensk sångfinal (retroactively often referred to as Melodifestivalen 1966) was the selection for the eighth song to represent Sweden at the Eurovision Song Contest, held at the Cirkus in Stockholm on 29 January 1966.

It was the seventh time that Sveriges Radio (SR) used this system of picking a song.