Orasay, inspired by the western isles of Scotland, will be a 50-cover dining room in Notting Hill.
It comes after the pair, who oversee Vauxhall’s Brunswick House, launched St Leonard’s in Shoreditch in June.
Orasay’s seafood-focused menu will offer ‘simple, approachable dishes’ using oysters, langoustines, scallops, razor clams, crabs and lobsters from the Hebrides.
The menu will also feature vegetables, honey and eggs sourced from the chefs’ organic farm in West Sussex.
A 60-bin wine list, priced from £25 to £125, will offer younger wines by the glass and carafe. There will also be a selection of bottled reds and whites, and rarer wines from Boxer’s personal cellar.
The restaurant's interior design will focus on 'simplicity', with a separate private dining room available for up to 12 guests.
Boxer will launch Orasay as chef patron, while Clarke will continue to cook at St Leonards alongside supporting the restaurant's creative direction. Both chefs will continue their involvement with Brunswick House.