Maire O'Flynn, and her husband Peter, were celebrating at the Lough Eske Castle Hotel, when Parker, 49, turned up at the hotel for a meal with her husband, Matthew Broderick, and some friends.
The 'Sex and the City' star took the time to pose for a photograph with the bride and complimented her on how well she looked.
The actress, best known for her role as Carrie Bradshaw in the hit TV show, owns a holiday home in Kilcar, County Donegal.
"But a few of the other guests thought it would be a missed opportunity if I didn't get a photo on my big day with such an iconic celebrity," said O'Flynn.