The airspace above the airport subsequently reopened with flights taking off again, local media reported citing airport officials.
The incident is the latest in a series of drone sightings across Europe that have sparked security concerns and disrupted air travel. On Friday, Berlin-Brandenburg Airport also diverted flights following a drone alert.
While this is the first reported drone sighting over Brussels Airport, suspicious unmanned aircraft were spotted earlier this month over several Belgian military bases. Defense Minister Theo Francken said those drones were believed to be attempting to spy on fighter jets and ammunition depots.
An investigation is underway into the incursions over the Kleine Brogel air base in northern Belgium.
This article has been updated.
