A total of 490,819 passengers chose London’s most central airport, 4% up (+19,300) compared to July 2018, which previously held the 32-year record.
It means the airport is on track to welcome over five million annual passengers by the end of the year for the first time.
During July, home carrier British Airways, which has broadened its range of leisure routes from London City Airport, saw a large boost in numbers on Greek island routes, with Skiathos passengers up 51% year-on-year and Mykonos up 39%.
Popular city break destination, Florence, also saw a 9% increase in passengers. The airline started a new route to Split in Croatia on 21st June, joining existing sun-seeker destinations including Ibiza, Malaga, Mallorca and Bergerac.
Buoyant load factors on LOT Polish Airlines’ new routes - Budapest, Warsaw and Vilnius - also boosted numbers, along with more capacity on flights operated by Dutch flag carrier, KLM.
The boost to leisure traffic reflects an ongoing trend at London City Airport, with more holidaymakers choosing the convenience of the East London airport, as well as people visiting friends and relatives either in London, the rest of the UK, or overseas.
Last year, Civil Aviation Authority (CAA) survey data identified that the proportion of business and leisure passengers is now evenly split, 50/50.
Richard Hill, Chief Commercial Officer at London City Airport, said: “The summer peak has delivered record-breaking passenger numbers, with continued demand from business and leisure travellers for the speed, convenience and customer experience of London’s most central airport, with a choice of 44 destinations.
“The boost in numbers during July reflects an ongoing trend towards welcoming more leisure travellers, including East Londoners and their families using the airport on their doorstep.
"As we continue with a £500 million transformation, this achievement marks the latest progress towards being a London gateway for everyone.”
In addition to the busiest ever month, the airport also experienced its busiest day on record, on Monday 15th July 2019, when 20,487 passengers either arrived at, or departed from, London City Airport.