Any of the four isomeric alcohols of formula C4H9OH:
- n-Butanol, butan-1-ol, 1-butanol, n-butyl alcohol;
- Isobutanol, 2-methylpropan-1-ol, isobutyl alcohol;
- sec-Butanol, butan-2-ol, 2-butanol, sec-butyl alcohol;
- tert-Butanol, 2-methylpropan-2-ol, tert-butyl alcohol.
It can also refer to butanol fuel, a proposed alternative to gasoline.