Wolfe Tones singer Brian Warfield says Electric Picnic asked them to come back after last year's success.
The Irish band will play the main stage at the three-day festival in Co Laois in August.
They were announced as part of the 2024 line up along with Calvin Harris, Kylie Minogue and Noah Kahan.
The Wolfe Tones also played last year to massive crowds with many spectators not able to get into the tent.
Brian Warfield told Lunchtime Live it's great to be back again.
"I'm very excited about it I have to say," he said.
"It's great to be put back on the main stage which is fantastic.
"We never thought about it to be honest but we knew there was a great surge in the popularity of The Wolfe Tones over the last 10 years or so."
'It was unbelievable'
Mr Warfield said they only realised the size of the crowds after last year's show.
"We could feel it at the show, at the gigs, everywhere - I don't think anybody realised it until we went to Electric Picnic [last year] and then we were very humbled by the fact that so many people came along and so many young people came along to the stage," he said.
"We didn't realise it because we were inside, we could see what was inside, but we had no clue what was going on outside.
"When we saw the aerial photograph it was just unbelievable".
Mr Warfield said last year was a fantastic event.
"They were talking about it afterwards when we back into the dressing rooms," he said.
"They said inside and outside the tent they were singing their hearts out to every song that The Wolfe Tones song.
"It was just miraculous, it was fantastic".
Mr Warfield said he only got the news about their performance this morning.
"We didn't put any request in at all; we were just told that Electric Picnic would like us back again this year," he said.
"So yeah, it's great that we are on the main stage and I hope to see the great crowd that we had last year all getting a peep at The Wolfe Tones".
Mr Warfield added that the line up for this year is "fantastic".