Work on the interior of the terminal has included the installation of a new security search area which is reducing average queuing times to six minutes.
The World Duty Free area has also had a refit that as part of an overhaul of the retail area which has seen it grow by 30%.
Belfast City Airport chief executive Brian Ambrose said: "We’re delighted to see the finished terminal facilities and I am confident that those travelling through Belfast City Airport will be impressed.
“Speeding the passenger journey through security search, whilst maintaining the integrity of the process, is of the utmost importance.