Porters and the adjacent Covent Garden Grill, on Henrietta Street, will close on Monday (19 January).
The businesses, including members of staff, will be consolidated into a new 3,000 sq ft Porters restaurant, which is due to open this summer.
Both restaurants are owned by Richard, Earl of Bradford, former chairman of the Restaurant Association.
The Earl said it was with “much sadness” that the decision to close both restaurants was taken, but he added that redevelopment in the area had made the decision slightly easier.
“It’s been a most emotional time, because, after 35 years of running Porters, and more recently Covent Garden Grill next door, we are finally going to close our doors.
“We thank our team – some of who have been with us since the day that we opened – our suppliers and, of course, our enthusiastic and loyal customers from all around the globe.”
He added: “This, however, is hopefully a new beginning when we open as Porters in the historic market town of Berkhamsted.”
Neil Wornham, director of Porters, said the new site would be formed from the “very best bits” of both restaurants.
Porters specialises in traditional English food, with signature dishes such as steak and kidney pudding, and fisherman’s pie.
Covent Garden Grill, meanwhile, is known for its steaks, burgers and pies.
Wornham said it was important to find somewhere that “reflected the heritage that we have at Porters and also provide somewhere memorable for customers”.
He added: “For that reason, the new restaurant at Berkhamsted is perfect.”
The new tenancy deal at the Berkhamsted site was handled by property agent Shelley Sandzer, acting on behalf of Lothbury Estate.
Kit Alexander at Shelley Sandzer, said: “On behalf of Lothbury we managed to secure a fantastic new tenant in Porters.
“The deal reflects the quality and diversity of our contacts, and adds to the list of respected restaurant brands who work with us on new sites.”