A cigarette is a small roll of finely cut tobacco leaves wrapped in a cylinder of thin paper for smoking. The cigarette is ignited at one end and allowed to smoulder; its smoke is inhaled from the other end, which is held in or to the mouth and in some cases a cigarette holder may be used as well. Most modern manufactured cigarettes are filtered and include reconstituted tobacco and other additives.

The term cigarette, as commonly used, refers to a tobacco cigarette but can apply to similar devices containing other herbs, such as cloves or cannabis. A cigarette is distinguished from a cigar by its smaller size, use of processed leaf, and paper wrapping, which is normally white, though other colors are occasionally available. Cigars are typically composed entirely of whole-leaf tobacco.

Rates of cigarette smoking vary widely, and have changed considerably over the course of history – since cigarettes were first widely used in the mid-19th century. While rates of smoking have over time leveled off or declined in the developed world, they continue to rise in developing nations. Nicotine, the primary psychoactive chemical in tobacco and therefore cigarettes, is addictive. Statistically each cigarette smoked shortens the user's lifespan by 11 minutes. About half of cigarette smokers die of tobacco-related disease and lose on average 14 years of life. Cigarette use by pregnant women has also been shown to cause birth defects, including mental and physical disabilities. Secondhand smoke from cigarettes has been shown to be injurious to bystanders, which has led to legislation that has banned their smoking in many workplaces and public areas. New research has shown that thirdhand smoke, which is the residue of cigarette chemicals left on clothes, furniture and carpets after second hand smoke has gone, increases the probability of lung-related diseases. Cigarettes are the most frequent source of fires in private homes, which has prompted the European Union and the United States to ban cigarettes that are not fire standard compliant by 2011.