The cyanate ion is an anion consisting of one oxygen atom, one carbon atom, and one nitrogen atom (OCN⁻), in that order, and possesses 1 unit of negative charge, borne mainly by the nitrogen atom. In organic compounds the cyanate group is a functional group.

The cyanate ion is an ambident nucleophile in nucleophilic substitution because it can react to form an alkyl cyanate R-OCN (exception) or an alkyl isocyanate R-NCO (rule). Aryl cyanates (C₆H₅OCN) can be formed by a reaction of phenol with cyanogen chloride (ClCN) in the presence of a base.

Cyanates are salts of cyanic acid for example potassium cyanate (KNCO).

The 'cyanate ion is relatively non-toxic in comparison to cyanides. Use of this fact is made in cyanide decontamination processes where a permanganate oxidation converts toxic cyanide to cyanate.

Cyanates | Functional groups