Passengers using Luton airport rose by 21.5% last month to more than one million.
The October figure took the number above 12 million passengers in 12 months for the first time in the airport’s 77-year history.
It marks 19 months of consecutive growth in passenger numbers for the airport.
Work has started on a £110 million development project to increase Luton’s annual capacity from 12 million to 18 million passengers.
Chief executive, Nick Barton, said: “Reaching this milestone in our passenger numbers is a hugely significant moment and a clear indication that our expansion is very timely.
“With air capacity in the southeast being such a pressing issue we are committed to playing our part to meet demand and providing the best possible experience for all our passengers.”