甲酸盐（英语：Formate）是CHOO离子或HCOO（甲酸减去一个氢离子）。此为最简单的羧酸阴离子。

• 甲酸乙酯，CH₃CH₂(HCOO)
• 甲酸钠，Na(HCOO)
• 甲酸铯，Cs(HCOO)
• 甲酸甲酯，CH₃(HCOO)
• 氯甲酸甲酯，CH₃OCOCl
• 原甲酸三乙酯
• 原甲酸三甲酯，C₄H₁₀O₃

Formate (IUPAC name: methanoate) is the anion derived from formic acid. Its formula is represented in various equivalent ways: CHOO or HCOO or HCO₂. It is the product of deprotonation of formic acid. It is the simplest carboxylate anion. A formate (compound) is a salt or ester of formic acid.