Camellia sinensis is a species of evergreen shrub or small tree whose leaves and leaf buds are used to produce tea. It is of the genus Camellia (Chinese: 茶花; pinyin: cháhuā, literally: "tea flower") of flowering plants in the family Theaceae. Common names include "tea plant", "tea shrub", and "tea tree" (not to be confused with Melaleuca alternifolia, the source of tea tree oil, or Leptospermum scoparium, the New Zealand tea tree).

C. sinensis var. sinensis and C. s. var. assamica are two major varieties grown today.[2] White tea, yellow tea, green tea, oolong, dark tea (which includes pu-erh tea) and black tea are all harvested from one or the other, but are processed differently to attain varying levels of oxidation. Kukicha (twig tea) is also harvested from C. sinensis, but uses twigs and stems rather than leaves.

The generic name Camellia is taken from the Latinized name of Rev. Georg Kamel,[3] SJ (1661–1706), a Moravian-born Jesuit lay brother, pharmacist, and missionary to the Philippines.

Carl Linnaeus chose his name in 1753 for the genus to honor Kamel's contributions to botany[4] (although Kamel did not discover or name this plant, or any Camellia,[5] and Linnaeus did not consider this plant a Camellia but a Thea).[6]