Ethylenediaminediacetic acid (EDDA not to be confused with Ethylenediamine diacetate(CAS:38734-69-9) also known as EDDA) is the organic compound with the formula C<sub>2</sub>H<sub>4</sub>(NHCH<sub>2</sub>CO<sub>2</sub>H)<sub>2</sub>. It is a derivative of two molecules of glycine, wherein the amines are linked. It is a white solid. It is one of several aminopolycarboxylic acids.
The conjugate base is a tetradentate ligand. A representative complex is Na[Co(EDDA)(CO<sub>3</sub>)].