Nitrosyl cyanide, a blue-green gas,[1] is the compound with the molecular formula ONCN.

The compound has been invoked as a product of the oxidation of cyanamide catalyzed by the enzyme glucose oxidase.

It is strongly bent at the internal nitrogen, analogous to the structure of nitrosyl chloride.

[1] The compound can be created by the reaction of nitrosyl chloride and silver cyanide at low temperatures.

It is not typically isolated, but trapped by Diels-Alder reactions, e.g. with butadiene.