Accenture Tower (500 West Madison) is a 42-story, 588-foot (180 m) skyscraper in Chicago, Illinois.

Located between Clinton and Canal Streets on Madison Street, the structure was designed by the architecture firm Murphy/Jahn in a late modernist style.

The building, previously named the Northwestern Atrium Center and Citigroup Center, was constructed between 1984 and 1987 on the air rights obtained by the destruction of the head house of the 1911 North Western Station.

The building contains retail and offices, and is connected to the platforms of Ogilvie Transportation Center.

[2] On December 8, 2006, a man opened fire in a law office located on the 38th floor of the Citigroup Center.