Glycolonitrile, also called hydroxyacetonitrile or formaldehyde cyanohydrin, is the organic compound with the formula HOCH2CN.

Because glycolonitrile decomposes readily into formaldehyde and hydrogen cyanide, it is listed as an extremely hazardous substance.

In January 2019, astronomers reported the detection of glycolonitrile, another possible building block of life among other such molecules, in outer space.

[4] Glycolonitrile is produced by reacting formaldehyde with hydrogen cyanide at near-neutral pH, but with small amounts of catalytic base.

As the product of polymerization is an amine with a basic character, the reaction is self-catalysed, gaining in speed with ongoing conversion.