The detached Victorian property, which has 10 letting bedrooms, has been acquired by George and Jess Hardy, who already run a local holiday cottage company.
Jess is also undertaking a “career change”, having worked as a biomedical scientist for the NHS.
The property was sold by the hotels agency team at Colliers, acting on behalf of Joe and Sarah Warzecha who have decided to retire after five years spent running the venue.
Diamond Lodge, which dates back to 1860, is located within walking distance of Ambleside village and Lake Windermere.
The property was originally known as Cherry Trees, but it was closed and underwent a “comprehensive refurbishment” in 2015 after being acquired by the Warzecha family and they then reopened it as Diamond Lodge.
Haydn Spedding, consultant to Colliers, said: “Joe and Sarah are well known and much respected guest house operators, having owned several in Ambleside and Windermere over the last 30 years. They are retiring to live near Kirby Lonsdale.
“Diamond Lodge offers discerning visitors luxurious Bed and Breakfast accommodation in a picturesque and accessible setting, and it will undoubtedly provide excellent business opportunities for the new owners George and Jess at a time when the Lake District World Heritage site is proving hugely attractive to the growing staycation market.”