Ketones are organic compounds that contain a carbonyl group bonded to two carbon atoms. The general chemical formula for ketones is RCOR', where R and R' are alkyl, aryl, or vinyl groups. The carbonyl group consists of a carbon atom double-bonded to an oxygen atom (C=O).

Ketones can be thought of as derivatives of aldehydes, in which one hydrogen atom of the aldehyde group has been replaced by an alkyl, aryl, or vinyl group. Ketones are widely used in industry as solvents, fuels, and starting materials for the synthesis of other organic compounds.