The move from this summer comes five months after rivals CityJet axed the route, with BA claiming to now be the largest airline at the Docklands airport.
BA executive chairman Keith Williams said the expansion would increase BA’s daily Scotland-London flights to 57 - its highest number ever.
One in 25 of the airline’s total London passengers are on Scottish routes.
Mr Williams told The Scotsman: “London City is the business area of London and has become quite a big operation, where we are now the largest player.
“If the demand is there, we will equally fly more from Glasgow too.”
BA also flies from Aberdeen to London City, from Edinburgh and Glasgow to Gatwick, and from all three Scottish airports to Heathrow.
Mr Williams was in Scotland today to mark completion of work on the 500th Airbus aircraft at its maintenance base at Glasgow Airport, and open a new £1.5 million executive lounge at Edinburgh Airport.
The hangar looks after 40 per cent of the BA fleet, including nearly all of its short-haul airport such as most of those on Scotland- London routes.
The base is operating at full capacity, and some work is having to be done by other companies, suggesting BA may look to expand the operation, which opened 48 years ago.
The workforce has increased by one third from 240 to 330 in the last four years, and has carried out BA’s Airbus maintenance since 2003.
Each of the 112 aircraft are brought in for major servicing every 18 months, which involves up to 12 days’ work including stripping down the cabin, engines and other parts.
Mr Williams said: “It is testimony to the expertise, professionalism and dedication of everyone at British Airways Maintenance Glasgow (BAMG) – past and present – that, after almost half a century, they continue to play a vital role in engineering at British Airways.
“The safety, security and technical integrity of our aircraft are of paramount importance to British Airways, and the engineering function, including the work carried out at BAMG, is central to that principle.”
Tom Williams, Airbus’s Glasgow-born vice president, programmes, said: “The 500th of British Airways’ fleet of single-aisle Airbus aircraft is a significant milestone and demonstrates the important role of the A320 family as the backbone of the company’s short and medium range fleet.”
BA’s Edinburgh lounge has been almost doubled in size to 730 square metres.
The lounge was designed by Glasgow-based Graven Images and features artworks from Edinburgh School of Art.
Edinburgh Airport chief executive Gordon Dewar said: “The opening of this fantastic new lounge marks the single biggest investment by British Airways in a Scottish airport.”