More than 15,000 passengers travelled between Cornwall Airport Newquay and London Heathrow last month.
The first month of the new link attracted a 4% rise in passengers compared to the London Gatwick route in the same month last year, despite there being fewer overall seats available.
The airport also saw a 3% growth in passenger numbers as a whole in April 2019 compared to April last year.
Airport MD, Al Titterington, said: “We’re delighted to see the route perform so strongly in its first month, the additional frequencies better support (London) day returns for business and make connectivity to/from other global destinations that much easier.
“The Heathrow link is key for Cornwall, for both outbound travel and inbound tourism and we are confident that we will continue to see the route grow further in the coming months.”
Flybe launched the route on March 31, flying four times a day, seven days per week between Newquay and London Heathrow.