The group, who are currently on their UK tour, told fans that they are gearing up to play the two-day event at Bangor in May.
"We were talking to Ian [Watkins] and one guy asks if he's playing North Wales any time soon," a source told DS.
"He replied, 'Isn't that where the Radio 1's Big Weekend is? Because well, you haven't heard this from me, but we'll see you there, but I didn't say it, if you get what I mean'."
Pixie Lott was recently confirmed as the first act to perform at the festival. Additions to the lineup are expected over the next few weeks.
Ticket details for the event are yet to be announced.
Radio 1's Big Weekend was held at Swindon's Lydiard Park last year and included performances from Lily Allen, The Prodigy and Dizzee Rascal.