The Departed star was in Dublin where he attended Weir & Sons and Patek Philippe's new 2022 watch Exhibition at the exclusive Chapter One restaurant.
Presenter and singer Nicky was also at the event and shared a hug with the actor before the pair posed for a photograph together.
Sharing the photos on Instagram, Nicky joked that "he wants to join Westlife". He added: "Great to see this guy last night".
Mark seems to be enjoying himself in Ireland where he found time for a round of golf at the five star Limerick resort, Adare Manor.
In a video on Instagram, Mark said he was "back in the homeland" and declared it "the greatest golf course in Europe by far".
It comes following reports recently that Mark is set to open a branch of his famous Wahlburgers restaurant in Dublin.
In an interview with the Sunday Business Post, co-owner Paul Wahlberg said said they are looking to open their first branch outside of North America in Covent Garden in London, but Dublin is also being looked at.
"We want to find a high-profile Dublin city centre location that can highlight the signature open-kitchen concept."
Mark Wahlberg set the burger chain up with his brothers Paul and Donnie back in 2011, and have since opened 27 branches across America and Canada since then.
According to reports, they're looking to open a number of branches across Ireland over the next ten years.
Dancing with the Stars host Nicky is currently preparing for Westlife's Wild Dreams tour which kicks off in Dublin in July.