One AT&T Center (formerly One SBC Center and One Bell Center) is a 44-story building in downtown St. Louis, Missouri at 909 Chestnut Street on the Gateway Mall. It is Missouri's largest building by area with 1,400,000 square feet (130,000 m2). The building is leased entirely by AT&T, except for some small retail locations in the lobby.
The building was built to replace the Southwestern Bell Building as the Southwestern Bell world headquarters. However, in a series of mergers the headquarters moved to San Antonio, Texas and was renamed AT&T.
In 2006 Inland American Real Estate Trust, a subsidiary of the Inland Real Estate Group in Chicago bought the building for $205 million. AT&T then signed a 10-year lease to be the sole tenant.
At one point, 4,800 AT&T employees worked in the building but that number has dropped through layoffs, outsourcing and telecommuting to approximately 2,000. In September 2013, AT&T announced they would vacate the building over the next 12 months, although their lease on the building runs through 2017.