“Gearóid Ó Cairealláin’s death is a great loss for all those who work for the use of the Irish language: its rights, its literature, and its place in the daily life of people,” Higgins added.
“He served as president of Conradh na Gaeilge, but his contribution was much wider than that.”
On Saturday, Kneecap posted on social media that Mr Ó Cairealláin was “an Irish language revolutionary, community activist, loving father, husband and an inspiration to many”.
They dedicated their concert that night – described as the “largest Irish language gig in the city’s history” – to him.
“Nothing would have made him prouder,” they added.
Conradh na Gaeilge said Mr Ó Cairealláin “will be remembered as one of the great leaders and pioneers in the Irish language movement in Belfast”.
It said he was a founding member of Irish language station Raidió Fáilte and Meánscoil Feirste, west Belfast’s Irish language secondary school.
“There can be no denying the incredible influence and impact Gearóid had on the Irish language movement, not only in Belfast, but throughout the country,” said Conradh na Gaeilge president Paula Melvin.
“He leaves behind him an undeniable legacy that will be an immense source of inspiration for us all throughout the future.”