Tonic

Tonic may refer to:
 * Tonic water, a drink traditionally containing quinine
 * Soft drink, a carbonated beverage
 * Tonic (physiology), the response of a muscle fiber or nerve ending typified by slow, continuous action
 * Tonic syllable, the stressed syllable of a word
 * Herbal tonic, a herbal medicine with tonic effects
 * Tonic (music), a concept of music theory
 * Tonic (band), an American rock band
 * Tonic (Tonic album), 2010
 * Tonic (music venue), a New York City music venue, 1998–2007
 * Tonic (Medeski Martin & Wood album), 2000
 * Tonic (radio program), Canadian radio program
 * Tonic suit, a garment made from a shiny mohair blend that was fashionable among the Mods of the mid 1960s
 * Windtech Tonic, a Spanish paraglider design
 * Tonic (film), a Bengali film