More than a thousand people who attended Latitude in July later tested positive for Covid.
The Festival, at Henham Park near Southwold, was the first event of its kind after the relaxation of lockdown rules. It attracted 40,000 visitors from across the country.
Data released by Suffolk County Council shows that 1050 people tested positive for Covid in the days after Latitude. Of those 175 lived in Suffolk.
Festival goers were offered the chance to get their Covid jabs at a mobile clinic and two acts had to cancel because they tested positive before the event.