The Mallard, which sits on a golf course in Gullane, was taken over by Iain and Flora Clark in 1963 when they moved to the area with their four children.
Mr Clark, who chose the pub name after being inspired by wildlife in Aberlady Bay, died four years later on Christmas day but the family stuck together to keep business going.
Now, 57 years later, daughter Susan Law and her husband Cameron, who have been running the pub together since Mrs Clark died in the 90s, have handed the keys over.
"It's certainly a bittersweet end,” said Susan, 63, “The Mallard has been home for a long time.
"After dad died mum, who was proper Highland stock being a crofter’s daughter, showed that ‘just get on with it attitude’ until she passed away and we kept it going.
"It’s amazing it’s been in our family for almost 60 years.
“Goodbyes have been difficult, but the hotel is in good hands.”
The Mallard has been sold to Watchman Inns, a pub group owned by four families who live in the East Lothian town.
According to Susan, the new owners plan to preserve the original building but the name of the pub will be changed to The Watchman.
"The buyers will keep its character and they are interested in keeping it as a community hub,” Susan said.
"My dad always used to say ‘hospitality with informality’ which is what we strove to achieve with it.
"Mum had her own way of putting it though and used to say the place offered ‘a drop of Highland hospitality in the Lowlands’ which I always thought was very special.”
Reminiscing about guests and staff she met and worked with in the years spent running the hotel, Susan remembered a few familiar faces who stopped by.
"I won’t forget the moment the boxer Henry Cooper came in and held my son in the palm of his hand,” she said, laughing at the memory.
"Alastair Campbell also came in a couple of times, he’s my mother’s first cousin.”
But the couple, who also ran a cafe in the town called The Ugly Duckling, said the sense of community is what they will miss most about the hotel.
"The feedback since we announced our retirement has been wonderful.
"People who stayed at the hotel years ago have been in touch to share memories which is very touching.
"The staff were also amazing and I want to make a special thank you to Diana Davidson who worked with us at the hotel for 32 years, she is really part of the family.”
The Mallard team has been heavily involved with supporting nearby charity Muirfield Riding Therapy, an organisation set up to provide riding therapy for disabled children.
Susan received an MBE for her work with the organisation and she will continue to work with them in her retirement.
Karen Chapman, one of the new owners, said: “We are really excited to be taking on this new project and look forward to bringing more to the community.
"We wish Susan and Cameron the best of luck in their well-deserved retirement and are looking forward to seeing them the other side of the bar.”