苯基硼酸（化学式：PhB(OH)₂）是一种烷基硼酸，由硼酸中的一个羟基为苯基所替换而得到。

白色斜方晶体，在水和苯等溶剂中溶解度不大，易溶于乙醚和甲醇。分子为平面型，理想的分子对称性为C_2v。硼原子为 sp 杂化，含有一个空的p轨道。两分子苯基硼酸通过分子间氢键形成缔合二聚体。

暴露在空气中或者在加热条件下，容易脱水，形成三分子的聚合物。

Phenylboronic acid or benzeneboronic acid, abbreviated as PhB(OH)₂ where Ph is the phenyl group C₆H₅-, is a boronic acid containing a phenyl substituent and two hydroxyl groups attached to boron. Phenylboronic acid is white powder and is commonly used in organic synthesis. Boronic acids are mild Lewis acids which are generally stable and easy to handle, making them important to organic synthesis.