Almost 11 million people took foreign package holidays in the first nine months of this year - a rise of 13 per cent on the same period in 1997, says travel company Thomas Cook.
But analysts warned that fears of a recession combined with the recent stock market turmoil meant less people would travel abroad next year.
The most popular destination was the Spanish Balearic Islands - best known for the resorts at Majorca, Menorca and Ibiza - although the number of visitors fell 5 per cent.
The second most popular country was Greece, which achieved the fastest visitor growth rate of 33 per cent. The World Cup boosted French visitor levels, which were up 21 per cent, while Italy suffered a decline of 13 per cent.
Andrew Windsor, managing director for Thomas Cook Retail, said: "It has been a bumper year for holidays, fuelled by a renewed `feel-good factor' in the UK and an abundance of building society windfall payments."
The figures, released at the annual convention of the Association of British Travel Agents in Marbella, Spain, are the latest sign the foreign travel market has enjoyed a boom.
A survey in August estimated that 20 million people - a record - would visit foreign destinations this year, a rise of 5 per cent. And official statistics showed that in the first half of the year, trips to North America rose almost 25 per cent, and travel to other long-haul destinations rose 14 per cent. Western Europe only gained 9 per cent.
Over the same period spending abroad rose more than 16 per cent. But the euphoria may be short-lived. Clive Vaughan, research manager at Verdict, said the holiday industry had benefited from the pounds 3bn of building society windfalls but warned that the market was braced for a downturn.
"The holiday market is fuelled by older people and the recent stock market collapse means they are feeling a lot less confident about the levels of their investment. 1999 looks to be a lot more challenging than 1998," he said.
Nancy Cockerell, managing editor of Travel and Tourism Intelligence, said the travel market was closely linked to the fortunes of the economy. "What we have seen in the past 12 months is the strong pound and a `feel- good factor'. Now we are looking at a slow-down." However, Thomas Cook said bookings for 1999 were up 7 per cent.
Britons' appetite for holidays and business travel has even eaten into the country's public finances.
Spending on foreign holidays helped send the balance of payments into the red by pounds 3.2bn in the first three months of the year, the biggest deficit for five years. Spending on overseas trips rose more than pounds 300m to pounds 4.8bn during January to March.