HollyFrontier(HollyFrontierCorp; abbreviated: HFC) is a leading U.S. oil refining company founded in 1947 and headquartered in Dallas, Texas; in July 2011, Holly Corporation and Frontier Oil Company merged to become Holly Frontier Corporation. The company, which provides gasoline, diesel and jet fuel, was ranked No. 819 on the Global 2000 in 2014.