The party's new offices are at 160 Blackfriars Road in a building which also houses branches of Pret a Manger, Sainsbury's Local and Costa Coffee.
Other office tenants include credit reference agency Experian.
The new office is just two stops from Westminster on the Jubilee line from Southwark station.
The party's national executive committee met at the Blackfriars Road offices for the first time this week, with several NEC members sharing photos of the view across the rooftops of Waterloo on social media.
Labour had its offices in Walworth Road between 1980 and 1997 when it left the borough for Millbank Tower closer to the Palace of Westminster.
The former party HQ – renamed John Smith House in 2004 – is now a Safestay hostel.
The former London Labour Party HQ at Herbert Morrison House in Walworth Road is currently being turned into a branch of the Creams gelato and waffle chain.
Most recently the national party has been based in Victoria Street.
160 Blackfriars Road changed hands for £125 million in 2021. It is now owned by Maya Capital LLP and AnaCap Financial Partners who intend to build a new hotel in the former car park at the rear of the building.
Plans for the hotel to be part of the 'lean luxury' Ruby group have fallen through and it will now form part of the Motel One chain.
The change of operator means that the developer now intends to increase the number of bedrooms in the hotel by 53 to 222 without increasing the size of the new building. An application to amend the planning permission is currently under consideration by Southwark Council.
The freeholder of the site is the Bridge House Estates, the charity administered by the City of London Corporation charged with the upkeep of Thames crossings including Blackfriars Bridge.