A total of 1,104,264 people passed through the doors of the capital's airport last month - an increase of 1.8% on the same period in 2013.
Edinburgh Airport first passed the one million passenger mark last summer when it welcomed over two million travellers between July and August.
Gordon Dewar, the airport's chief executive, said: "Breaking the 1.1 million passenger mark in July was another milestone for us and I'm delighted to be celebrating this with our teams across the airport who work hard to give passengers a great experience."
Glasgow Airport also recorded its busiest July in six years after more than 840,000 passengers travelled through - a rise of 1.1% compared to last year.
Amanda McMillan, managing director, said the highlight of July for the airport was "serving as the gateway to the Commonwealth Games".
She added: "It has always been the case that when the city does well, the airport does well and with events such as the World Pipe Band Championships, the Ryder Cup and MTV European Music Awards all still to come, both the city and the airport have much to look forward to."
Overall there was an increase of 9.2% in the number of people using Aberdeen Airport with 366,562 passengers.
There were increases reported across the board at the site as helicopter passengers were up 5.1%, domestic passengers by 8.4% and international traffic growth of 12.9%.
Carol Benzie, managing director, said: "Not only have we recorded growth for the past month but this growth has touched each sector of our operation which demonstrates that we have a healthy, growing business.
"This is incredibly encouraging and shows yet again the buoyancy of the region. We have recently felt the impact of the summer holiday get-away and the increase in charter flights, as well as other growth through the business, provides a real boost to the airport and to the passengers."