The Greek Cup 2005-06 was the 64th staging of The Greek Football Cup, or Greek Cup, competition. This season's edition was the first to be entitled "SINCO Greek Cup" after SINCO Insurance Brokers.

The competition started on 20 August 2005 and concluded on 10 May 2006 with the Final, held at the Pankritio.

Olympiacos claimed this season's Greek Cup with a 3-0 victory over AEK Athens.

The 64th Greek Cup Final was played at the Pankritio Stadium and it was the first Greek Cup Final to be played in Heraklion since 1931. Similarly to the semi-finals, there would be no replay even if the match was drawn; instead, extra time would be used to decide the winners. If extra time failed to separate the two sides, the match would go to penalty kicks.

The Greek Football Cup (Greek: Κύπελλο Ελλάδος Ποδοσφαίρου), commonly known as the Greek Cup or for sponsorship reasons the Football Cup OPAP, is a Greek football competition, run by the Hellenic Football Federation.

Because it involves clubs of all standards playing against each other, there is the possibility for "minnows" from the lower divisions to become "giant-killers" by eliminating top clubs from the tournament and even theoretically win the Cup.

The holders of the Greek Cup are Olympiacos, who beat fellow Super League Greece side Atromitos 2–1 on a.e.t, in the 2012 final held on 28 April 2012.

The Greek Cup began in 1931. In its early years, entry was optional. Teams were paired against each other by the football associations, without a draw taking place. Later on, for many years, a proper draw took place and two-leg matches were held up to the final. In the 90s, the qualifying matches were played in groups. The winners of the groups played against each other up to the final in two-leg matches.