The cyanate ion is an anion with the chemical formula written as [OCN]^- or [NCO]^-. In aqueous solution it acts as a base, forming isocyanic acid, HNCO. The cyanate ion is an ambidentate ligand, forming complexes with a metal ion in which either the nitrogen or oxygen atom may be the electron-pair donor. It can also act as a bridging ligand. Organic cyanates are called isocyanates when there is a C-NCO bond and cyanates when there is a C-OCN bond.

The cyanate ion is an anion with the chemical formula written as [OCN]^- or [NCO]^-. In aqueous solution it acts as a base, forming isocyanic acid, HNCO. The cyanate ion is an ambidentate ligand, forming complexes with a metal ion in which either the nitrogen or oxygen atom may be the electron-pair donor. It can also act as a bridging ligand. Organic cyanates are called isocyanates when there is a C-NCO bond and cyanates when there is a C-OCN bond.