ThyssenKrupp AG is a German industrial engineering and steel production multinational conglomerate. It resulted from the 1999 merger of Thyssen AG and Krupp and has its operational headquarters in Duisburg and Essen. The company claims to be one of the world's largest steel producers, and it was ranked tenth-largest worldwide by revenue in 2015. It is divided into 670 subsidiaries worldwide. The largest shareholders are the Alfried Krupp von Bohlen und Halbach Foundation and Cevian Capital. ThyssenKrupp's products range from machines and industrial services to high-speed trains, elevators, and shipbuilding. The subsidiary ThyssenKrupp Marine Systems also manufactures frigates, corvettes, and submarines for the German and foreign navies.

Thyssen was a major German steel producer founded by August Thyssen. The company merged with Friedrich Krupp AG Hoesch-Krupp to form ThyssenKrupp in 1999.