Stars come out for mother of all lunches to raise funds for UNICEF
O'Callaghan, accompanied by his mother Marie and wife Jenny, was taking time out ahead of today's Pro12 game against Leinster.
Donncha and Jenny welcomed their third child, six-month-old baby Robyn, last year.
The couple also have two young daughters, Sophie and Anna.
The 34-year-old rugby star said, with so many away matches over the years, he missed out on quality time with his girls. "It's tough because of what I do. You have to travel a lot and that's a hard part of it," he said.
Proceeds from yesterday's lunch will go towards helping mothers in vulnerable situations around the world to give birth in safe environments.
The event – held in association with the Irish women's clothes brand, Fran and Jane – included a fashion showcase.
Guests were also given a first look at a new UNICEF video starring O'Callaghan as part of the campaign to eradicate polio. It followed the rugby player's recent fact-finding mission to Nigeria.
UNICEF Ireland's chief executive, Peter Power, updated the gathering on the organisation's activity around the globe helping children to survive and thrive.