The Excel exhibition centre in the Royal Docks is to become a temporary hospital housing 500 patients.
Work will begin imminently to convert the venue as local hospitals see increased admissions relating to Covid-19. Capacity could increase to 4,000.
The project follows similar conversions seen in nations with large growth in coronavirus cases.
The military are believed to be assisting with conversion work when work commences and are looking at other sites across London and the country for similar projects.