Luton is the latest airport to report a record summer this year with 2.6 million passengers handled in July and August.
Last month’s total of 1.4 million passengers was 16% up on August last year, marking 17 months’ consecutive growth.
Alongside increased passenger numbers, the airport has announced 19 new routes and attracted four new airlines this year.
A £100 million development scheme is planned to raise annual capacity from 12 million to 18 million by 2026, as well as upgrading facilities.
Chief executive, Nick Barton, said: “This record-breaking summer has demonstrated the increasing popularity of LLA and has highlighted the need for expansion in order to meet the demands of our passengers.
“The £100 million we are investing will ensure that we are able to give all our passengers a quick, easy and good value service at London Luton.”