Karen posted photos of the happy couple on social media after they celebrated their marriage at the Lyons Estate in Co Kildare at the weekend.
It was a double celebration for Clondalkin man Kenneth as he turned 35 on the big day.
Karen looked stunning in her gown with lace pliquey detail with full sleeves.
Beaming Karen could not contain her excitement as she shared the happy occasion with her followers on Instagram.
"My husband, he looked amazing in that suit. #7/1/17 #ourwedding," she wrote.
One snap shows Karen being walked down the aisle by her dad, with the caption, "My dad walking me in, I was so nervous."
Kenneth and Karen were together back in 2008 when he claimed a silver medal at the Beijing Olympics.
Karen featured in much of the high-profile coverage of Kenneth, proudly supporting her boyfriend with friends and family at home while he fought for Ireland.
They split soon after though as the pressures of the spotlight took a toll on their relationship.
They got back together some time ago though and have one child together.
The former boxing champion now works as an addiction counsellor and is a Fine Gael councillor representing Clondalkin on South Dublin County Council.