Olean is a town in Cattaraugus County, New York, United States. The population was 1,963 at the 2010 census. The name is derived from the Latin word "oleum" due to the discovery of crude oil in nearby Ischua.
The town of Olean is in the southeast corner of the county. The city of Olean, originally the village of Olean, is bordered by the town on three sides.
The area of Olean was first settled around 1805. The town of Olean was established in 1808 as the first town in the county. The northern part of the county was spun off as the town of Hebe in 1812; the western part became the town of Perry (later Perrysburg) in 1814, Great Valley was formed in 1818, Hinsdale in 1820, and Portville in 1837.
The village of Olean was originally named "Hamilton", after Alexander Hamilton, but was called "Olean Point" until simplified to Olean in 1823.
The name "Olean" was suggested for the area due to the oil found in the vicinity. The famed Wenro Oil Spring, discovered by the Franciscan missionary Joseph de La Roche Daillon in 1627 was located about upstream (northeast) of Olean Point. The original town hall burned in 1884, prompting a law that forbade wooden structures in parts of the town.