HNO

HNO may refer to:
 * Croatian National Committee (Hrvatski Narodni Odbor), an organization founded by the Ustaša Branimir Jelić
 * Croatian National Resistance (Hrvatski narodni otpor), an organization founded by the Ustaša Maks Luburić
 * Hockey Northwestern Ontario
 * Nitroxyl
 * hno, ISO 639-3 code for the Northern Hindko language of Pakistan