The 1966 Icelandic Cup was the seventh edition of the National Football Cup.
It took place between 16 July 1966 and 23 October 1966, with the final played at Melavöllur in Reykjavik. The cup was important, as winners qualified for the UEFA Cup Winners' Cup (if a club won both the league and the cup, the defeated finalists would take their place in the Cup Winners' Cup). Teams from the Úrvalsdeild karla (1st division) did not enter until the quarter-finals. In prior rounds, teams from the 2. Deild (2nd division), as well as reserve teams, played in one-legged matches. In case of a draw, the match was replayed.
KR Reykjavik won their 6th Cup in 7 seasons, beating the Icelandic champions, Valur Reykjavik, 1 - 0 in the final.
First round
Second round
Third round
Quarter finals
Entrance of 6 clubs from 1. Deild
Semi finals
Final
KR Reykjavik won their sixth Icelandic Cup and qualified for the 1967–68 European Cup Winners' Cup.