磷（拉丁语：Phosphorum，化学符号：P）是一种化学元素，它的原子序数是15。

磷是一种易起化学反应的、有毒的氮族非金属元素。它的化学反应活性和毒性取决于形态不同而有所区别。

磷化氢燃烧的火叫鬼火。

Phosphorus is a chemical element with symbol P and atomic number 15. As an element, phosphorus exists in two major forms—white phosphorus and red phosphorus—but due to its high reactivity, phosphorus is never found as a free element on Earth. With few exceptions, phosphorus bearing minerals are in the maximally oxidised state as inorganic phosphate rocks.