Hawksmoor St Pancras will be the group's eighth UK restaurant joining branches in Manchester, Liverpool, Edinburgh and London.
The new venue will be at the St Pancras Hotel and will boast the brand's first Chef's Table and a new Martini bar in the Grade I listed space.
The iconic hotel is a byword for Victorian Gothic grandeur and was built by architect George Gilbert Scott to put up travellers arriving into St Pancras Station.
When it opened in 1873 as The Midland Grand Hotel it was the last word in luxury with a grand staircase and fireplaces and gold leaf in every bedroom.
It closed in 1935 and was used at rail offices before falling into disrepair, until a campaign to rescue it from demolition brought it back to life.
Since June this year, the five star hotel has been owned by the