The event was due to run from Friday to Sunday, but organisers said that weather had delayed the site build.
In a statement on Facebook, organisers said: “We are truly devastated to announce that Gwên Gwen Festival 2023 has been cancelled. The team have worked tirelessly over the past nine months, especially this week under extremely challenging circumstances with weather making the site build difficult and as a result of these challenges and the associated added extra costs, we have made the very difficult decision to cancel the event.
“This is not a decision we have taken lightly and sincerely apologise for the disappointment this will cause. We want to thank all the ticket-holders, volunteers, artists, traders, contractors, security and everyone who has helped under extremely difficult circumstances and gone above and beyond to make this work.”
Organisers also said that refunds are currently being processed and an email will be sent to all ticket-holders.
Early on Friday, headline act Example pulled out of his Sunday slot because of alleged contract breaches.
On his Instagram story, the artist said that full fees had not been paid and that there was a lack of communication with the organisers of Gwên Gwen Festival.
He added: “The promoter of this event has breached a number of points in the contract. We have had zero communication regarding the stage, technical and backstage setup. Something we cannot just turn up to unprepared and essentially would be going into the show blind.”
Organisers said they would release an additional statement today (Monday).