The move, which has been attributed to the ongoing regeneration of the Low Line along the Southbank and into Borough, will see the food, drink and event destination relaunch this week on Southwark Street in a space a mere 200 feet from its original location on the corner of Southwark Bridge Road and Union Street.
Its adjoining live music venue Omeara will, however, remain under the arches in its current location.
The move follows the closure of St Felix Square, which was launched by Venue Group last year.
Flat Iron Square's new home will boast an on-site craft beer brewery and taproom, and will continue to feature a revolving offer of food truck operators that changes monthly.
The first four brands confirmed to take up residence in Flat Iron Square's new space include Louisiana-style sandwich slingers Po' Bros; focaccia-style pizza brand Good Slice; burger specialist Gamekeeper; and Lebanese street food operator Lil’Watan.
Flat Iron Square originally launched back in 2016.
Venue Group also operates Goods Way food hall and music venue in King's Cross.