Oleum is an unincorporated community in Contra Costa County, California, United States. It is located on the Southern Pacific Railroad 6 miles (10 km) east-southeast of Point Pinole, at an elevation of 203 feet (62 m). An oil refinery is located at Oleum, hence the name from "petroleum".
Oleum is located on the Mexican land grant Rancho El Pinole made to Ygnacio Martinez. A post office operated at Oleum from 1910 to 1951.
- ^ a b c d e f "Oleum (Contra Costa County, California)". Geographic Names Information System. United States Geological Survey. Retrieved May 11, 2014.
- ^ a b "FIPS55 Data: California". FIPS55 Data. United States Geological Survey. February 23, 2006. Retrieved May 11, 2014.
- ^ a b c Durham, David L. (1998). California's Geographic Names: A Gazetteer of Historic and Modern Names of the State. Clovis, Calif.: Word Dancer Press. p. 675. ISBN 1-884995-14-4.