The Bristol International Balloon Fiesta is held annually during August in Bristol, England. Teams from the UK and other parts of the world bring their hot air balloons to the site and participate in mass ascents where as many as 100 balloons may launch at a time.

The event was first held in 1979 and is now one of the largest in Europe. It is common to have crowds of over 100,000 on each of the four days of the festival. It takes place in a large country estate Ashton Court. Mass launches are made twice a day, at 6am and 6pm, subject to weather conditions.

One popular attraction is the night glow, when balloons are inflated and glow to music after dark. These are held on the opening Thursday night at approx 9:30pm, followed by a spectacular fireworks display. There is another night glow at the same time followed by the fireworks on the Saturday night. Some people see these as the highlight of the fiesta.

The balloon makers, Cameron Balloons are near to the fiesta site, in Bedminster, and make many of the special shaped balloons, which have included Rupert the Bear, The Scottish Piper, Bertie Bassett, and the Tesco Trolley. Many shapes have also attended the fiesta from abroad, over the years a UFO and a beaver have travelled from the USA, a Kiwi Bird from New Zealand, and an upside down balloon from Holland.

In the past, the fiesta used to be held in the second week of September, but due to cancellations of flights and the muddy ground because of bad weather, it has been moved in the start of August. This had had a great effect as more flights manage to fly, cancellations are now normally due to high winds.

In 2003, the weight of crowds returning from the Balloon Fiesta and Ashton Court festival put such a great strain on the Clifton Suspension Bridge that it was decided to close the bridge to all traffic, including pedestrians, during these events from 2004 onwards.