Unveiled on Monday by a team of abseilers descending the face of Tate Modern, the logo is designed to emphasise the geographical breadth of London's Olympics as well as the Thames' place at the hub of the capital's communities and cultural attractions.
The logo was created by Clerkenwell agency Kino Design, whose clients include BT, CNBC Europe and celebrity chef Gary Rhodes.
The agency has been paid £10,000 for the work and has assigned copyright for it to London 2012, the company behind London's bid.
London 2012 chairman Barbara Cassani said: "The Olympic Games embody competition, harmony and human endeavour. To me, the ribbon in the logo brings to mind the medals that Olympians and Paralympians from around the world will come to London to compete for in 2012."
The logo, chosen from 1100 entries, was selected by a panel of design experts, Olympians, future athletes and ordinary Londoners. It will be used on all bid materials, including advertising and building wraps, badges and pens.
"We chose the River Thames because it flows through the centre of London and is the point at which many of the city's waterways and communities meet," said Andy Stansfield, a founder of Kino Design.
"It is also symbolic of the people from all over the world who flow in and out of London, defining its style, personality and vibrancy."
David Magliano, the bid's marketing director, wants the logo to become a familiar sight across London as the process continues.
Magliano is looking to use unusual media space such as check-in screens at airports to promote the bid.
The bid's management team is now complete, with Magliano and Cassani joined by Air Miles and Nectar founder Keith Mills as chief executive.
London is up against cities including New York, Paris and Madrid in the race to host the 2012 Games. It will learn the outcome of the contest in July 2005.