BellSouth Corporation is an American telecommunications holding company based in Atlanta, Georgia. BellSouth was one of the seven original Regional Bell Operating Companies after the U.S. Department of Justice forced the American Telephone & Telegraph Company to divest itself of its regional telephone companies on January 1, 1984.

In a merger announced on March 5, 2006 and executed on December 29, 2006, AT&T Inc. (originally Southwestern Bell) acquired BellSouth for approximately $86 billion (1.325 shares of AT&T for each share of BellSouth) The combined company retained the name AT&T. The merger consolidated ownership of Cingular Wireless and YELLOWPAGES.COM, both of which were joint ventures between BellSouth and AT&T.

With the merger completed, wireless services previously offered by Cingular Wireless are now offered under the AT&T name. In addition, BellSouth has formally become AT&T South, its Bell Operating Company doing business as AT&T Southeast, and ceased doing business under the BellSouth name on June 30, 2007.