Nicotiana ( /ˌnɪkɵʃiˈeɪnə/) is a genus of herbs and shrubs of the nightshade family (Solanaceae) indigenous to North and South America, Australia, south west Africa and the South Pacific. Various Nicotiana species, commonly referred to as tobacco plants, are cultivated and grown to produce tobacco. Of all Nicotiana species, Cultivated Tobacco (N. tabacum) is the most widely planted and is grown worldwide for production of tobacco leaf for cigarettes. The genus is named in honor of Jean Nicot, who in 1561 was the first to present tobacco to the French royal court. Nicotiana germination is usually 2–5 days in 27 °C (81 °F) weather.

The word nicotiana (as well as nicotine) was named in honor of Jean Nicot, French ambassador to Portugal, who in 1559 sent it as a medicine to the court of Catherine de' Medici.

It is most commonly smoked in the form of cigarettes or cigars. Tobacco is native to both American continents and was used by native cultures by around 3000 BC.^{[citation needed]} Employed as an anthelmintic, it has been smoked, in one form or another, since about 3000 BC.^{[citation needed]} Tobacco has a long history of ceremonial use in Native American cultures. It has played an important role in the political, economic, and cultural history of the United States.