1-Nitroso-2-naphthol is an organic compound with the formula C10H6(NO)OH.

It is one of several possible nitrosonaphthols, and the most studied for applications as an indicator and a dye.

[2] 1-Nitroso-2-naphthol can be prepared by treatment of 2-naphthol with nitrous acid:[3] Its conjugate base forms deeply colored complexes with iron(II) and cobalt(II), complexes [M(C10H6(NO)O)3]2-.

[4] The deep colors of these complexes results from the delocalized bonding within each five-membered chelate ring.

These species can be classified as nitroso complexes.