Between 11am and 1pm, the street was full of people of all ages donning their favourite hats to help raise money for charity.
All proceeds from the event were donated to Polegate charity Children with Cancer Fund.
Betsy Langford, one of the event’s organisers, said: "HatFest was never about competition – it was about participation.
“Our aim was simply to bring people together, celebrate our wonderful community and support the fantastic independent businesses that make Green Street so special.
“Seeing so many smiling faces made all the hard work worthwhile, and we hope this will become an annual event that continues to grow."
Take a look at Rupert Kirby’s excellent pictures from the event:
9. In pictures: Eastbourne's inaugural Old Town HatFest
Eastbourne's inaugural Old Town HatFest. Photo: Rupert Kirby Photo: Rupert Kirby
10. In pictures: Eastbourne's inaugural Old Town HatFest
Eastbourne's inaugural Old Town HatFest. Photo: Rupert Kirby Photo: Rupert Kirby
11. In pictures: Eastbourne's inaugural Old Town HatFest
Eastbourne's inaugural Old Town HatFest. Photo: Rupert Kirby Photo: Rupert Kirby
12. In pictures: Eastbourne's inaugural Old Town HatFest
Eastbourne's inaugural Old Town HatFest. Photo: Rupert Kirby Photo: Rupert Kirby