According to figures from the tourism ministry, the total figure is a 19.4% increase on the same period last year – and the majority of them have been on low-cost airlines.
Companies like Ryanair, Easyjet and Vueling that have led the way, capturing 52.4% of total air traffic, while more traditional airlines captured just 47.6%.
The UK led the low-cost arrivals with 9.66 million passengers, representing 36.8% of the total.
It was a 16.6% increase on last year.
The Brits were followed by Germany and Italy, both with 11.4% of budget arrivals.
Barcelona-El Prat airport accounted for 24.3% of all low-cost travelers during the first seven months of the year, up 8.2% to 6.3 million passengers.
Meanwhile Malaga airport, which registered 3.17 million low-cost passengers until July, a 14.1% increase, captured 12.1% of total traffic.
In July, the Costa del Sol terminal added 644,769 passengers, 10.3% more than in 2016.
By communities, Catalonia, the Balearics and Andalucia have benefitted most from the tourism boost.
Catalonia received more than seven million foreign tourists arriving by low-cost airlines, which represents 26.9% of the total number of travelers arriving by this route, 9.2% more than in 2016.
In July alone it increased by 6.9%, to over 1.36 million travelers.
The Balearic Islands is the second most benefited community with four million passengers by, 20.5% more than last year, capturing 15.4% of the total.
It is followed by Andalucia with 3.87 million passengers, a 13.5% increase.