Tonic water (or Indian tonic water) is a fizzy soft drink flavoured with quinine. The drink gains its name from the medicinal effects of this slightly bitter flavouring.

The quinine was added to the drink as a prophylactic against malaria, since it was originally intended for consumption in tropical areas of India and Africa where that disease is endemic.

Tonic water originally contained only carbonated water and quinine, and it contained a large amount of the latter. However, most tonic water today contains a medically insignificant amount of quinine, and is thus used for its flavor only. It is consequently less bitter, and is also usually sweetened. Some manufacturers also produce diet tonic water.

In the United States, the Food and Drug Administration limits tonic water quinine to 83 ppm (83 mg per litre if calulated by mass), which is one-half to one-quarter the concentration used in therapeutic tonic.

Tonic water is often used as a mixer for alcoholic spirits, especially gin (the mixture commonly known as a gin and tonic).

Tonic water with lemon or lime flavor added is known as bitter lemon or bitter lime, respectively. Such soft drinks are more popular in Europe than in the United States.

Tonic water will glow under ultraviolet light, due to the quinine in it.

Brands of tonic water:

• Canada Dry
• Cantrell
• Cunnington
• Perrier
• Schweppes
• Royal Club
• Nordic Mist by Coca-Cola Company
• Kinley by Coca-Cola Company
• Krest by Coca-Cola Company
• Antarctica by Ambev (Brazil)
• Finches by Gleeson (Ireland)

Soft drinks | Cocktail mixers | Carbonated drinks | Quinine

Tònica | Tonic Water | Tónica (bebida) | Toniko | Tonika | トニックウォーター | Tonik | Água tônica | Tonic-vesi | 通寧水