Three flights from Southampton, Malaga and Alicante were even kept in a holding pattern in the sky above the airport.
One woman wrote: 'So just about to take off when drone spotted so flight stopped!
While Leeds Bradford is a relatively smaller regional airport - the 15th busiest in the UK, according to the UK Civil Aviation Authority - the Friday afternoon delays came in the midst of peak summer travel season.
A drone sighting has been reported but this has not yet been confirmed.
A West Yorkshire Police spokesman confirmed flights were affected by a drone sighting.
A spokesperson for Leeds Bradford Airport said: 'We are investigating reports of a drone over the airport.
The airport re-opened 45 minutes later.
Flights at Leeds Bradford Airport in the United Kingdom were held for almost an hour on Friday after a drone was seen flying near the runway.
It's after an inbound flight spotted the device flying near the airport on its approach at around 12.55pm.
An emergency was declared at the popular Yorkshire airport where flights have either been suspended or diverted to Humberside and Manchester.
Officials say they monitoring the situation and working with police. To be clear, this is *not* an Extinction Rebellion action and not something we'd support.