亚溴酸是溴的一种含氧酸，不稳定，见于反应的中间体。化学式为HBrO₂，其中，溴的氧化态为+3。

通过次溴酸和次氯酸的阳极氧化反应：

HBrO + HClO → HBrO₂ + HCl

通过次溴酸的歧化反应：

2 HBrO → HBrO₂ + HBr

通过溴酸和氢溴酸的反应合成

2 HBrO₃ + HBr → 3 HBrO₂

Bromous acid is an acid with the formula HBrO₂. It has bromine in the +3 oxidation state. The salts of bromous acid are called bromites. The acid is not stable and only occurs as an intermediate; for example, in the oxidation of hypobromites.