Thorleif Enger (born 31 October 1943) is a Norwegian businessperson and was Chief Executive Officer of Yara International. Enger was educated at the University of Colorado where he earned his PhD in Structural Engineering. He worked for Royal Dutch Shell until 1973, after which he moved to Norway to work for Norsk Hydro. He was director of the Oseberg oil field 1982–86, and from then until 1996 was president of the exploration and production division. He was then executive vice president of Hydro Oil and Gas until 1999, when he became executive vice president of Hydro Agri, and when this division was demerged to create Yara in 2004 he became its CEO. He announced his retirement in September 2008. Enger has been president of the International Fertilizer Industry Association, and has been a