Bitumen is a category of organic liquids which are highly viscous, black, sticky and wholly soluble in carbon disulfide. Asphalt and tar are the most common forms of bitumen.

In British English, 'bitumen' is often used interchangeably with both 'asphalt' and 'tar'. In American English, 'bitumen' is most commonly used in engineering jargon to explicitly include both asphalt and tar based materials. In Australian English, 'bitumen' is used as the generic term for road surfaces.

Vessels for heating of Bitumen or bituminous compounds are a usual exclusion of public liability insurance policies.

Bitumen is obtained by using fractional distillation. This distills fractions of different compounds from crude oil. Bitumen being the heaviest and being the fraction with the highest boiling point, it appears as the bottommost fraction.