五碘化磷是一种无机化合物，化学式为PI₅。固态时，它是一种离子晶体[PI₄]I，稍高温度立即分解。它可以由碱金属碘化物和溶解在碘甲烷中的五氯化磷反应来制备。

Phosphorus pentaiodide is an inorganic compound with formula PI₅. The existence of this compound has been claimed intermittently since the early 1900s. The claim is disputed: "The pentaiodide does not exist (except perhaps as PI₃I₂, but certainly not as PI₄I ...)".