Tea tree (Melaleuca alternifolia) is an evergreen shrub or small tree in the myrtle family (Myrtaceae) native to Australia. It has narrow aromatic leaves, papery bark, and small pale flowers, and the leaves are the part most commonly used in herbal and essential oil preparations.

Tea tree is especially well known for the steam-distilled oil made from its leaves, which is widely used in topical blends, washes, and household products. In herbal use it is valued for its strong cleansing aroma, though the essential oil is intended for external use only.