Hawksmoor group's remaining two Foxlow restaurants in London's Clerkenwell and Balham will close on 28 June.
Co-owner Will Beckett announced the closure, saying they "couldn't see a future where Foxlow grew as a business" and said they plan to focus on the Hawksmoor brand. Some staff from the restaurants will move over to Hawksmoor.
The group's Soho Foxlow closed and the lease was sold in April, following the closure of Foxlows in Chiswick and Stoke Newington last year.
Co-owner Will Beckett said: "After a fantastic six years we have made the decision to close the two remaining Foxlow restaurants. Once Soho closed, we started to receive further offers. We decided to sell Foxlow Clerkenwell and simultaneously close the Balham restaurant, which seems better to us than continuing to trade and leave staff, suppliers and customers in a period of uncertainty. We'll now be focusing on making sure that those people are looked after in the right way.
"When we opened our first Foxlow we wanted to create a great neighbourhood restaurant, doing the things that we believe in: sourcing food from the best British farmers and fishermen, treating staff well and allowing them in turn to show our customers the kind of hospitality that we enjoy giving and receiving ourselves.
"However, in the end we couldn't see a future where Foxlow grew as a business. With Foxlow closed we will be able to focus exclusively on Hawksmoor, which continues to be extremely successful and we are very proud that it continues to thrive and grow. Many of the people who worked in Foxlow restaurants are moving over to Hawksmoor to continue to build their careers, which we believe is testament to the exceptional culture we have here.
"To everyone that supported Foxlow and have made the last six years so enjoyable for us all, thank you so much, and we look forward to your continued support with Hawksmoor for many years to come."
Foxlow was Will Beckett and Huw Gott's neighbourhood-style restaurant brand. Hawksmoor was founded in 2006 and has grown to nine sites in London, Manchester and Edinburgh.