The line, formerly known as Crossrail, will open in December 2018 and connect Reading and Heathrow in the west with Shenfield and Abbey Wood in the east.
The six partners will be offered 12 months of sector-exclusive advertising rights across the line’s stations – which include ten new stations on the central section of the line – and opportunities to partner with TfL on marketing integrations.
The Elizabeth line is expected to carry 200 million passengers a year, TfL said, which is more than all of London’s airports combined.
It features a range of cutting edge advertising infrastructure, including large and small digital screens and digital escalator "ribbons".
Graeme Craig, director for commercial development at TfL, said: "As the Elizabeth line will redefine London, we are also redefining our approach to commercial partnerships.
"No other city is as defined by its transport system as London. The roundel and Tube map are symbols of our city, known and trusted around the world. We look forward to working with six commercial partners to launch the newest addition to London’s global brand."