Assam is a black tea named after the region of its production, Assam, India. Assam is the world's largest tea-growing region, lying on either side of the Brahmaputra River, and bordering Bangladesh and Burma (Myanmar). This part of India experiences high precipitation; during the monsoon period as much as 10 to 12 inches of rain per day. The daytime temperature rises to about 103F, creating greenhouse-like conditions of extreme humidity and heat. This tropical climate contributes to Assam's unique malty taste, a feature for which this tea is well known.

Assam tea is manufactured specifically from the plant Camellia sinensis var.assamica(Masters).This tea, most of which is grown at or near sea level, is known for its body, briskness, malty flavor, and strong, bright color. Assam teas, or blends containing Assam, are often sold as "breakfast" teas. English Breakfast tea, Irish Breakfast tea, and Scottish Breakfast Tea are common generic names.

Though "Assam" generally denotes the distinctive black teas from Assam, the region produces smaller quantities of green and white teas as well with their own distinctive characteristics.

Historically, Assam is the second commercial tea production region after southern China. Southern China and Assam are the only two regions in the world with native tea plants. Assam tea revolutionized tea drinking habits in the 19th century since the tea, produced from a different variety of the tea plant, yielded a different kind of tea.