Acetate, or ethanoate, is the anion of a salt or ester of acetic acid. The term can also refer to an acetate disc used in audio record production.

In Organic chemistry, the acetate ion has the formula CH₃CO₂^-, and is the conjugate base of acetic acid.

Acetate can refer to cellulose acetate, especially fibers or other derived products. Acetate can be found in many household products.

Historically (prior to the discovery of actinium) the abbreviation Ac (or AC) was sometimes used in chemical formulas to indicate the acetate ion. For example, the formula for sodium acetate might be given as "NaAc", rather than the more modern "CH₃COONa" or "NaC₂H₃O₂".