Some 2.3 million people will head abroad this weekend as schools break up for the summer holidays, travel organisation Abta said.
The western Mediterranean is the most popular destination for British holidaymakers travelling overseas this summer.
Bookings to Portugal are up 23% year-on-year, while demand has also grown for trips to Spain (22%) and Cyprus (16%).
Abta reported that long-haul destinations have performed well, with Florida proving to be one of the most popular destinations.
Airports are expecting high passenger numbers between Friday and Sunday, with 530,000 jetting off from Heathrow, 350,000 from Gatwick, 128,000 from Stansted and 80,000 from Luton.
Birmingham airport is set to welcome around 60,000 departing travellers, with 55,000 flying from Newcastle and 15,000 from Cardiff.
The Eurostar, Eurotunnel and ferry ports are also set for a bumper weekend.
There has also been "strong sales" for holidays in Devon, Cornwall and the Channel Islands as some people opt for a domestic break.
Mark Tanzer, Abta chief executive, said this weekend is "one of the busiest in the travel calendar".
The RAC has warned that congestion on the roads caused by the annual end-of-term summer getaway is set to be "dramatically worse" than in 2015.
It estimated that 14.4 million motorists will embark on car journeys for overnight breaks between Thursday and Sunday, some 5.4 million more than during the same period last year.
Saturday is due to be the single busiest day with 4.5 million journeys for short breaks and longer holidays.