The local rivals were set to meet at Inonu, but the match was called off after a torrential downpour in Istanbul
The city rivals were due to meet at 18.00CET at Inonu, but after a heavy downpour, referee Huseyin Gocek ruled that the water-sodden pitch was unplayable.
The Turkish FA (TFF) has announced that the derby will be replayed on April 16.
Galatasaray finished the first phase of the Turkish season on top of the Super Lig, while Besiktas ended up in fourth place, 22 points behind their local rivals.
Another Istanbul team, Fenerbahce, host Trabzonspor on Sunday as they get their play-off campaign under way.