Nick Holmes has left his position as managing director of the five-AA-star, 61-bedroom Rockliffe Hall hotel near Darlington, County Durham, after six years in the role.
Simon Roberts, previously hotel manager at the hotel, is now running the property as resort manager.
Holmes joined the property - privately owned by Steve Gibson, chairman of Middlesborough Football Club - a year prior to its opening in 2009 at a cost of £50m. Developed around an 18th century country hall within a 375-acre estate on the banks of the River Tees, the business includes two restaurants, a spa and championship golf course.
Holmes said that his time at Rockliffe Hall had reached its natural conclusion, having created "a natural force" within the industry.
"When I accepted the post back in 2008 my primary task was to lead the opening and establishment of Rockliffe to help create one of the country's premium five-star resort destinations," he said. "I am proud to say that, with the magnificent team I have had the privilege of helping to build and lead, this has been mostly achieved and I must now move onto the fresh challenges available to me.
"I want to thank each and every team member past and present who have contributed to our success."
Holmes also thanked Rockliffe's chairman and Gibson for giving him the opportunity of leading what he calls a "dream project".
"I am sure that this is only the beginning for Rockliffe Hall and it can only go from strength to strength in the years to come."
Rockliffe Hall, which hosted the Team GB football team prior to the London 2012 Olympic Games, recorded a loss of £1.1m for the year to 30 June 2013, compared with a loss of £3m during the previous year, according to the hotel's latest annual report to be lodged at Companies House. Annual occupancy was 70%, while turnover increased from £8.4m to £8.9m, year-on-year.