IHI Corporation is a Japanese engineering corporation headquartered in Tokyo. It operates in four main business areas, providing a diverse range of products. Its four business areas are Resources, Energy, and Environment; Social Infrastructure and Offshore Facilities; Industrial Systems and General-Purpose Machinery; and Aero Engine, Space, and Defense.

It manufactures ships, space launch vehicles, aircraft engines, marine diesel engines, gas turbines, gas engines, railway systems, turbochargers for automobiles, plant engineering, industrial machinery, power station boilers and other facilities, suspension bridges, and other structures.

The company strives to contribute to society through technology, combining diverse engineering capabilities to meet the increasing global needs for energy, urbanization and industrialization, and transportation efficiency.