Veteran swimmer Mark Foster was "blown away" after learning he will mark his fifth Olympic Games by carrying the British flag during the opening ceremony in Beijing on Friday.
Foster, 38, who will compete in the 50m freestyle, was chosen from a poll of all the British competitors.
Foster is the first swimmer to carry the flag since Anita Lonsbrough in 1960.
Foster, who made his Olympic debut at Seoul in 1988, said: "I was blown away when I was told, it was a big surprise and a huge honour. It's fantastic.
"Some of the most wonderful names in British sport have been Olympic flag-bearers.
"I really wanted to be picked but I didn't totally believe I would be.
"My heart was pumping when the announcement was made.
"Making the Olympic Games this time around was fantastic in itself, but this has really topped it off. It's phenomenal."
The announcement was made by Britain's chef de mission Simon Clegg at a Team GB reception hosted by the British Ambassador Sir William Ehrman and attended by HRH The Princess Royal.
Each of Team GB's team leaders had the option to nominate a candidate for flag-bearer, in consultation with their athletes.
Team leaders then voted on the shortlist of nominees in consultation with their athletes.
Foster, who competes for the University of Bath swimming club, has set five world records, seven European records, nine Commonwealth records and 19 British records during his long and illustrious career.
In June he became the first British man to swim the 50m in under 22 seconds and he returend to the world top 10.