Sodium oxalate, or disodium oxalate, is the sodium salt of oxalic acid with the formula Na₂C₂O₄. It is a white, crystalline, odorless solid, that decomposes above 290 °C. Disodium oxalate can act as a reducing agent, and it may be used as a primary standard for standardizing potassium permanganate solutions.

Formula: Na2C2O4