Airport bosses have confirmed the terminal was fully evacuated after an emergency fire alarm "was set off accidently" at about 8.50am this morning (Sunday).
The disruption lasted about 20 minutes before passengers were brought back into the airport.
Some flights to European destinations are believed to have been slightly delayed following the evacuation.
A Leeds Bradford Airport spokesperson said: "We can confirm that at 08:52am the terminal was evacuated after one of the emergency fire alarms was set off accidentally.
"Following a full evacuation, passengers were allowed back into the terminal at 09:10am.
"The airport is open and fully operational."