Oil is any of a number of nonpolar, hydrophobic, and viscous liquids.

Oil also often refers to:

• Cooking oil, any liquid fat used in food preparation
• Lubricant, a substance that reduces friction between surfaces
  • Lubrication, using a lubricant to reduce friction
  • Motor oil, any lubricant used in internal combustion engines
• Petroleum (crude oil), naturally occurring liquid found beneath the Earth's surface, or a derived product:
  • Fuel oil, liquid fuel burned for heat or power
  • Heating oil, liquid fuel

Oil or OIL may also refer to:

• Oil paint, paint with pigments suspended in an oil
• Oil painting, the process of using paints based on oils

• Oil (band), a group of Californian heavy metal musicians
• OiL, a band from Pennsylvania now called CKY
• Oil: Chicago Punk Refined, a compilation CD released by Thick Records
• Midnight Oil, also known as "The Oils", an Australian rock band
• "Oil," a Gorillaz track featuring Stevie Nicks, released on the 2023 album "Cracker Island."

• Oil, an early title of the U.S. TV series Blood & Oil
• Oil, the original title of 1980s soap opera Dynasty

• "Oil" (Dynasty), the debut episode of Dynasty
• "Oil" (The Young Ones), a 1982 episode of The Young Ones

• Oil (film), a 2009 Italian documentary
• Oil!, a novel by Upton Sinclair published in 1927

• Big Oil, a name used to collectively describe major oil corporations
• OIL (incorporations and corporate services), a company
• Office of Infrastructure and Logistics (European Commission) in Luxembourg
• Oil India Ltd
• Oil Insurance Limited, a mutual insurance company
• Oilexco (TSX: OIL, LON: OIL), an oil company

• Ontology Inference Layer or Ontology Interchange Language, an ontology infrastructure for the Semantic Web
• OSEK Implementation Language, a description language used in OSEK systems

• All pages with titles containing OIL or OILs
• All pages with titles beginning with Oil
• All pages with titles beginning with OIL
• Langues d'oïl (in Romance languages)
• OYL (disambiguation)