BigHospitality understands the group has acquired a site on Great Eastern Street in Shoreditch for its London debut.
It comes as Fat Hippo, which was founded in 2010 by Michael Phillips, looks to expand across the UK.
The group currently has six restaurants based in the North and Midlands including in Newcastle, Leeds, Liverpool and Nottingham. It also operates concession stands in Manchester, Sheffield and Edinburgh.
This year will see Fat Hippo establish bricks and mortar restaurants in Glasgow, Edinburgh and Cardiff, as it looks to establish permanent outposts around the UK.
A site in Birmingham's city centre has also been confirmed.
Fat Hippo serves an eclectic range of burgers such as the PB+JJ burger that features a double patty topped with peanut butter and bacon jam; the Great White Buffalo burger with buttermilk chicken, American cheese, smoked bacon, buffalo hot sauce and purple ‘slaw; and the eponymous Fat Hippo burger, which includes a double patty, American cheese, smoked bacon, chorizo, onion rings and 'Fat Hippo sauce'.
All burgers are served in toasted demi brioche and are served with 'Hippo-dusted' hand cut fries as standard.