The Belgian Cup 2005-06 was the 51st staging of the Belgian Cup which is the main knock-out football competition in Belgium.
After the first 5 rounds teams from the Belgian First Division entered the competition on November 10, 2005.
The sixth round ended on December 6, 2005 and saw the surprise defeat of Anderlecht to second division side Geel after penalty shootout.
From the quarter-finals on matches were played in two legs.
The final game was played at the King Baudouin Stadium on May 13, 2006.