Poplar Baths on East India Dock Road has reopened for the first time in 28 years after a major refurbishment.
The redeveloped Grade II-listed leisure centre contains a 25-metre swimming pool and a learner pool, as well as a large studio, sports hall and gym.
John Biggs, Mayor of Tower Hamlets, said: “I am thrilled that such a prestigious building has been brought back into use and will benefit the local community by providing a first class swimming pool and sports activities.
“Many people have memories of using the baths and are pleased to see it back in use for new generations to enjoy.”
The baths, on the East India Dock Road, first opened in 1852 to provide washing facilities for the poor following the Baths and Washhouses Act of 1846.
Claire Brady of Historic England said: “We are delighted to have been part of the journey to bring this building at risk and important piece of Poplar back to life.
“People will now be able to enjoy its facilities as well as appreciate the history and value of such a magnificent building.”
The baths were redeveloped in 1933, and despite suffering bomb damage during the Second World War remained open until 1988.
But soon afterwards the building fell into a state of dereliction. Then in 2010 a joint bid to re-open the facility by The Environment Trust, Swan Housing group, and the Poplar Baths Steering Group won approval from Tower Hamlets Council.
The council will be holding an open day on Saturday 13 August where residents can have a tour of the new centre as well as get involved in sports and activity sessions.