Dermot Crowley has succeeded Pat McCann as chief executive of the Dalata Hotel Group, the largest hotel operator in Ireland.
The hotel group, which owns the Maldron and Clayton hotels, had announced Mr McCann's retirement in March. He had been CEO of the company since 2007.
Dalata said that Pat McCann retired from the company's board with effect from October 31, and his employment by the company will cease on December 31.
Mr Crowley had been the company's deputy CEO.
John Hennessy, Dalata's Group Chairman, said Mr McCann had been instrumental in growing Dalata into the ambitious organisation that it is today.
"I would also like to take this opportunity to wish Dermot well as he steps into the role of CEO. It is an exciting time for Dalata and the board is confident in Dermot's ability to lead the company into the next phase," he said.
"We look forward to working with him in the period ahead," he added.