The location is the city's historic Jackson Park, near the University of Chicago where the president taught law before being elected to public office, a source familiar with the decision making told AFP.
A formal announcement will be made in the coming days.
The 540-acre park, named after the seventh US president Andrew Jackson, was commissioned in 1869, according to the city's park district. It is nestled on Chicago's famed waterfront, overlooking Lake Michigan and is also the site of the Chicago Museum of Science and Industry.
The Obamas last year picked Chicago as the host city for their library, instead of Honolulu in Hawaii or New York City, which were also bidding.
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They had since narrowed their choice down to two sites: Jackson Park and Washington Park, which lies not far away to the west of the University of Chicago.
Their decision determines which of two economically struggling, predominantly African-American neighbourhoods receive a boost in investment and jobs.
Anthony Clark, author of a book on presidential libraries entitled "The Last Campaign," said the Obamas made the more cautious and conservative choice in picking Jackson Park.
"The foundation will build the library where more people, resources, and infrastructure exist already," Clark said, "Rather than try to be the main economic engine for a renewal" of the neighbourhood around the other park being considered.
The foundation last month announced that the firms Tod Williams Billie Tsien Partners (TWBTA) and Interactive Design Architects (IDEA) were chosen to design the building.