A nitrile is an organic compound which has a -CN functional group. The -CN functional group is called a nitrile group. In the -CN group, the carbon atom and the nitrogen atom are triple bonded together. The prefix cyano is often used to indicate the presence of a nitrile group in a molecule. A cyanide ion is a negative ion with the formula CN^-. The -CN group is sometimes referred to as a cyanide group. Compounds with them are sometimes referred to as cyanides.

Nitrile groups in organic compounds can undergo various reactions when subject to certain reactants or conditions. A nitrile group can be hydrolyzed, reduced, or ejected from a molecule as a cyanide ion.

Nitrile rubber is a synthetic rubber co-polymer of acrylonitrile and butadiene.