Honest Burgers, the Active Partners-backed group, has secured a site in Soho, MCA understands.
The group has taken on the former Ittenbari Japanese restaurant site in Brewer Street.
The restaurant is set to open in September with c80 covers across two storeys and will include a late licence.
Shelley Sandzer acted on the deal.
The group currently operates 25 sites and has openings in the pipeline for London Bridge, Cardiff and Bristol, among others.
In February, the group secured an increased funding package, totalling £17m, from its banking partner Santander to help fund its growth pipeline.
The group has also been strengthening its senior team ahead of a fresh growth push, with Gary Mann, its chief financial officer, being promoted to the position of joint managing director at the start of the year.