The elegant Foster + Partners design, located at South Dock in the Isle of Dogs, is set to be the third tallest residential building in London once complete in 2022.
Previously a 1980s office block, the new development will provide 888 mixed tenure homes in the borough of Tower Hamlets and enough new commercial space to support 1,000 permanent jobs.
At ground floor level there will be 2.6 acres of new public squares, gardens and children's playspaces for the local community to enjoy.
The unique design includes a 45-degree architectural rotation which gives the majority of homes a riverside view, while allowing more light to reach the landscaped public gardens below.
The topping out comes after South Quay Plaza won the multi-storey award at the National House Building Council's (NHBC) annual National Health and Safety Awards in July. This is the second time the development has been awarded the honour.
Justin Tibaldi, Divisional Managing Director of Berkeley Homes (Capital), said: "South Quay Plaza is a landmark development for Berkeley Homes and at 68 storeys will be the tallest building we have ever developed. It will create high quality affordable and market homes in South Dock and a fantastic mix of welcoming public spaces for the whole community to enjoy. I want to thank all of our partners for helping to deliver this highly innovative project."
Ray O'Rourke, CEO of Laing O'Rourke, added: "Laing O'Rourke is proud to be working once again with The Berkeley Group. An Innovative, offsite-manufacturing approach has kept us on track and the team is due to complete construction well in advance of the contractual handover date. I look forward to seeing this exciting 68-storey addition to the changing skyline of London."