For four decades, Irish comic performer Brendan Grace has traveled the world performing at famous venues for luminaries like Frank Sinatra, Sammy Davis, Jr., Jack Nicholson and President Bill Clinton. This weekend, he’ll interrupt his Irish winter tour to fly to Florida and play at the auditorium of Jupiter High School in honor of a local bartender.

Cathleen Kelleher, like Grace an Irish native and a veteran behind the bar at Paddy Mac’s in Palm Beach Gardens and most recently The Bistro in Jupiter, was diagnosed last summer with breast cancer. As her health deteriorated to the point where she couldn’t work, friends rallied to find a way to help out.

This weekend, that help takes musical form with a benefit for Kelleher featuring Grace and several other local Irish and Irish-American musicians, including Tracy Sands, Hugh O’Neill, Keith Ahearn, Hilary O’Leary and the Killbillies.

Grace considers it one of his most important engagements.

“There’s a lovely community here, and we look out for one another. When something of this nature befalls somebody, we do something,” says Grace, well known not only in his native country for his family-friendly work on stage, screen and television, but in the Irish community around his adopted home in Tequesta.

Kelleher, 39, was not up to discussing the benefit. Grace says she is a private person who nevertheless “is not squeamish about the fact that there is publicity, that this is to pay for (treatment) for her illness. She’s a brave person.”

“She’s very well known here - she’s been here since she was 21,” says Declan Hoctor, owner of The Bistro and the organizer of the event. “Many people were coming in to me, asking if we were planning on doing anything for her, looking for ways to help. This makes it easy to help her.”

South Florida has a large Irish community, for what Grace says is a self-explanatory reason.

“Have you ever been in the Irish weather?” he jokes. “That will answer your question.”

When Hoctor moved to Florida 15 years ago, he tapped into that warm community through “going to bars like Paddy Mac’s or O’Sheas, getting to know the people with Irish connections, and hanging out in those places. When you socialize, you tend to hear very quickly when one of your own is in a bad situation.”

And in this case, that someone was Kelleher. A native of County Cork, where “they’re famous for their ability to tell a story,” Hoctor describes her as “just a beautiful, energetic, outgoing girl. She’s very engaging with people. She’ll go out of her way to say ‘Hi.’”

Kelleher was diagnosed with breast cancer at the end of August 2012 “at Stage 2, which rapidly progressed to Stage 3,” Hoctor says. The mass was too large to remove with surgery, so she underwent several rounds of chemotherapy, which seems to have dissipated it. Her prognosis is good, but she’s been unable to work for six months and is without health insurance.

Around the time that she stopped working, Grace and his wife Eileen stopped into The Bistro and inquired about Cathleen, whom they’d met more than a decade ago when she worked at Paddy Mac’s, since “Irish people have a tendency to gather in places where liquor is served,” Grace says wryly. “We’ve been friends with her for a long time, and when we got together with Declan, we asked what we could do to help.”

When the idea of a concert this winter was broached, Grace was eager to be involved, even though he knew he’d be spending that time touring in Ireland and would have to interrupt that to return to Florida for 10 days.

“I’m a huge supporter of the airline business,” he jokes. “But I was happy to do it. The community there, both Irish and non-Irish, means getting involved and helping out. That makes us feel good that so many people are doing it. There’s a lot of talent here. It’ll be a hell of a night.”