The suffix -oate is the IUPAC nomenclature used in organic chemistry to form names of compounds formed from carboxylic acids. They are of two types:

• Formed by replacing the hydrogen atom in the –COOH by some other radical, usually an alkyl or aryl radical forming an ester. For example, methyl benzoate is a molecular compound with the structure C₆H₅–CO–O–CH₃, and its condensed structural formula usually written as C₆H₅COOCH₃.
• Formed by removing the hydrogen atom in the –COOH, producing an anion, which joins with a cation forming a salt. For example, the sodium benzoate is an ionic compound with the structure C₆H₅–CO–O⁻ Na⁺, and its condensed structural formula usually written as C₆H₅CO₂Na.

The suffix comes from "-oic acid".

The most common examples of compounds named with the "oate" suffix are esters, like ethyl acetate, CH
₃COOCH
₂CH
₃.