Niamh O'Brien and Michael Flatley (2011).RollingNews.ie
O’Brien died peacefully at Beacon Hospital in South Dublin "following a period of illness", according to a representative.
Her husband, Flatley, paid tribute to O’Brien, describing her as his "beautiful wife" and "best friend".
"My heart is broken. I have lost my beautiful wife, Niamh, and my best friend. My gorgeous bride of twenty years has gone to the Lord in Heaven.
"She was the most loving mother, wife and person, and our lives will never be the same without her," Flatley said.
"Thank you for all the love and kindness you have shown us. Please keep Niamh, Michael St James, and out family in your thoughts and prayers," he continued.
Alongside the statement, which was shared online, Flatley posted a series of photographs of O’Brien, including images of her dancing, a photograph from their wedding and a picture of the couple with their son.
A representative said she passed away peacefully at Beacon Hospital in Dublin following an illness.
"The Flatley and O’Brien families are devastated by Niamh’s sudden passing and have asked that their privacy be respected as they come to terms with this heartbreaking loss.
"They express their sincere gratitude to the doctors, nurses and staff at Beacon Hospital who cared for Niamh over the past few weeks, and to everyone who has offered their kindness and support to the family," they added.
Niamh O'Brien and Michael Flatley.
From competitive dancing to international fame
Originally from County Meath, O’Brien began competing in Irish dancing at a young age and went on to reach the highest levels of the sport.
She finished fourth in the world championships at the age of 17 before leaving the competitive circuit to pursue a career in professional dance.
Michael Flatley and Niamh O'Brien.
O’Brien subsequently performed in several of Flatley’s internationally touring productions, including Riverdance, Lord of the Dance, Feet of Flames and Celtic Tiger.
She and Flatley married in October 2006 at a church in Fermoy, County Cork, just three kilometers from Castlehyde, the 18th-century estate that Flatley purchased in 1999 and later restored.
The couple welcomed their only child, Michael St James, in 2007.
* This article was originally published on Extra.ie.