The firm has acquired a 95 per cent stake through its Regional and City Airports division.
The airport was sold by Northern Irleand based property developer Mar Properties.
Ian Taylor, chief executive, of Balfour Beatty, said: "Blackpool International is a well-located airport with the potential to become a thriving international gateway to Lancashire and Cumbria.
"We will work together with the airlines and our local partners to help increase its penetration within this core catchment area and to play its part in attracting inbound visitors to the region.
"We believe that our approach will deliver significant, sustained growth in passenger traffic at the airport and will generate important economic benefits for it and for Blackpool. Our aim is to develop Blackpool to be the airport of choice for residents, businesses and visitors of Lancashire and Cumbria."
Blackpool Council owns a five per cent stake in the airport.
Coun Peter Callow, leader of Blackpool Council, said: "This is absolutely great news for Blackpool. The Airport has developed rapidly in recent years and I am confident that Balfour Beatty will be able to take it to an even higher level."
Airline operators at Blackpool include Jet2.com, Ryanair and Manx2.com.
The airport is expected to handle around 500,000 passengers this year travelling to 12 destinations in the UK, Ireland and mainland Europe.