Nearly 200,000 more passengers were handled by Stansted in June compared to the same month last year.
More than 1.85 million passengers passed through the airport last month, an increase of 11.7% over June 2013.
The monthly rate of passenger growth in June was the highest experienced for any month in the last eight years.
This was achieved despite the loss of 88 flights, cancelled at the end of the month due to French air traffic control strike action.
The annual number of passengers using the airport rose to 18.48 million, an increase of 4.2% over the previous 12 months.
Airport managing director Andrew Harrison said: “The continuing growth of passenger numbers at Stansted clearly demonstrates just how far the airport has come since being acquired by MAG last year.
“To experience our highest monthly rate of growth since 2006 is a fantastic achievement and sends a loud and positive message that Stansted is changing for the better.”
He added: “Stansted has a critical role to play in the coming years in meeting the UK’s need to increase connectivity. As the only airport in the congested southeast with significant room to grow, it’s vital we make the most of the infrastructure we already have.
“To this end, we will shortly begin consulting with our local communities on our proposed Sustainable Development Plan that considers the benefits and effects of how the airport might develop to make full use of the existing runway
“We have planning permission for 35 million passengers a year but could provide additional capacity with relatively low impacts, high benefits and supporting the UK’s economic growth ambitions in the most cost effective and sustainable way possible.”