And this year the yacht received a record score of 96%, the highest mark ever awarded to a visitor attraction in Scotland.
It was rated by national tourism organisation VisitScotland.
VisitScotland's quality assurance scheme, is the official measure of quality for tourism businesses.
Tourism businesses are assessed on the welcome, attitude, knowledge and efficiency of staff, as well as audience level, interpretation, maintenance and cleanliness.
With 308,906 visitors in 2015, the Royal Yacht last week announced 2015 as its best since its opening year in 1999.
Almost five million people from around the world have visited The Queen's former yacht since it opened to visitors in Edinburgh in 1998.
Britannia's chief executive Bob Downie said: "To be the best in Scotland once is a fantastic achievement, but to do this for 10 consecutive years is a phenomenal tribute to our staff who go the extra mile to ensure that all our visitors have a great experience when they visit Britannia.
"The true test of any great organisation is consistency of performance, delivering great value for time and money, year in year out, and there is no doubt that our pioneering approach to providing great customer experiences has underpinned our success."
Malcolm Roughead, VisitScotland's chief executive, said: "I'd like to congratulate Britannia on this fantastic achievement, which demonstrates an outstanding commitment to quality and excellence in every aspect of the business.
"Retaining the accolade of Scotland's best attraction for 10 years running, Britannia is setting the standards for tourism in Scotland, and it is a real testament to the total commitment shown by their staff to consistently deliver a world-leading customer experience."
The Royal Yacht Britannia has been judged as Scotland's best visitor attraction every year for the past decade.