Cinergy Corp. (/ˈsɪnərdʒi/ SIN-ər-jee) was an energy company based in Cincinnati, Ohio, United States, from 1994 to 2006.

Cinergy was created on October 24, 1994, from the merger of the Cincinnati Gas & Electric Company (CG&E) and Kentucky subsidiary Union Light, Heat & Power (ULH&P) with Plainfield, Indiana–based PSI Energy (Public Service Indiana).

In 2005, Cinergy announced a friendly acquisition by the larger Charlotte, North Carolina–based Duke Energy.

The Ontario government, across the border in Canada, followed suit at the request of New York Attorney General Eliot Spitzer.

The authentic display measures 36+1⁄2 by 47+1⁄2 feet (11.1 m × 14.5 m) long and imitates an O gauge, in which a quarter-inch on the model is equivalent to one foot on a real train.