Chiyoda Corporation (千代田化工建設株式会社 Chiyoda Kakō Kensetsu Kabushiki-kaisha?) (TYO: 6366) is a large Japanese engineering company specialising in industrial facilities, particularly oil refineries and LNG facilities. Most of its business takes place outside Japan, normally in the Middle East.
In the late 1960s it built the Jeddah and Riyadh refineries in Saudi Arabia; at present its large projects include LNG plants in Qatar, the Sakhalin-II project in eastern Russia, and a variety of specialist-chemical and pharmaceutical plants in Japan itself.
It had a 484 billion yen revenue and 23.5 billion yen profit in 2006.