Stansted in Essex had 7.6 million passengers pass through its gates between June and August making it the airport's busiest ever summer.
August was also the busiest single month on record at Stansted with 2.7 million passengers, up 9.9% over the same month in 2016.
Stansted has seen more than 25 million passengers in the 12 months to the end of August. That is a rise of 6% on the previous year.
The airport also had its busiest single day for the second month running as 94,785 passengers passed through the terminal on 14 August.
The top ten busiest ever days at Stansted are now all recorded in July and August this year.
Stansted is planning to build a new £130 million arrivals hall.