The light installations will feature on 17 bridges that span the Thames between Albert Bridge in Chelsea and Tower Bridge in the City.
"This is a really exciting opportunity to breathe new life through the heart of London each night in a new, permanent, fluid light art installation across the capital’s historic bridges. It will throw a spotlight on the river and its banks, and extend their daytime bustle and buzz into the darker hours, supporting London’s burgeoning night-time economy," Khan said.
"A dazzling, free outdoor art gallery, for Londoners and all of our visitors to enjoy would encourage new investment and promote our great city to the rest of the world.
"With the right design, we can remind the world that London continues to be the global leader in innovation, sustainability and artistic creativity.”
The Illuminated River plan will aspire to harness green and sustainable technologies, and will be the world’s longest free, permanent outdoor river gallery, creating a ribbon of light through the city at night and revitalising public spaces along the river’s banks.
The project has been commissioned by the Illuminated River Foundation and supported by the Rothschild Foundation, collaborating effectively with a number of organisations including the City of London, Network Rail and Transport for London.
Mark Boleat, policy chairman at the City of London Corporation, said: “This project will transform London’s historic river and the City of London Corporation is very proud to play a part in making it happen.
"We want the City of London to be at the heart of what looks likely to be the largest art project of its kind in the world."