"Police have made a declaration under the Public Safety and Preservation Act tonight at Brisbane Airport due an emergency situation," Queensland Police said in a statement.
A man who allegedly claimed to have a bomb has been arrested by police.
Police said in a statement that there were no injuries to police officers or any members of the public. Searches and further investigations in the airport are ongoing.
Nearby trains have also been stopped, according to police.
The incident reportedly took place in the airport's international terminal.
"[A] man took out a knife in departures just as we checked in," an eyewitness, Nick Sherrard, posted on Twitter.
Flights have been delayed due to incident.