The program is aiming to have 3,000 bikes and 300 stations by next summer.
Initial funding for the program will come from federal grants.
Currently, bike sharing in Chicago is a small private venture limited to 100 bikes at six stations at popular tourist destinations.
Officials say they don't see this as a bike program but as a new transit option.
"It's a way to link people from their last mile from the CTA stop to the train stations," said Chicago Department of Transportation Commissioner Gabe Klein. "It's a way for people to get to the grocery store."
The city's bike-sharing program is expected to be year-round.
Similar programs have already launched in cities like Boston and Washington, DC.
