Development officer Linda Ervine said a growing interest in the language had led to the need to expand.
Ms Ervine said a “taster” Irish class held three years ago had revealed a surprising level of interest in the language.
“We started a regular class two years ago which was meant to last for 15 weeks,” she said.
“At present, there are eight weekly classes held in the Skainos centre.
“We had to expand to cope with the increasing numbers. Now, around 90% of our learners are Protestants.
“People contact me on a weekly, even daily basis. All we have done is to open the door.”
As part of the growing interest in the Gaelic language in east Belfast, a further two classes, one for children and one for parents, are to be held at Dundonald High School.