Vanadium(II) oxide is the inorganic compound with the idealized formula VO.

VO is a semiconductor owing to delocalisation of electrons in the t2g orbitals.

VO is a non-stoichiometric compound, its composition varying from VO0.8 to VO1.3.

[2] Diatomic VO is one of the molecules found in the spectrum of relatively cool M-type stars.

[3] A potential use of vanadium(II) monoxide is as a molecular vapor in synthetic chemical reagents in low-temperature matrices.