"Toxic" is a song by American singer Britney Spears, released as the second single from her fourth studio album, In the Zone (2003). It was written and produced by Bloodshy & Avant, with additional writing from Cathy Dennis and Henrik Jonback. It was initially offered to Kylie Minogue for her album Body Language, but she turned it down. A dance-pop and techno-pop song with elements of South Asian music, "Toxic" features varied instrumentation, such as drums, synthesizers and surf guitar. It is played in the key of C minor with a tempo of 143 beats per minute. It is accompanied by breathy vocals and high-pitched Bollywood strings, sampled from Laxmikant–Pyarelal's "Tere Mere Beech Mein" (1981). Its lyrics draw an extended metaphor of a lover as a dangerous and addictive drug.

Britney Jean Spears is an American singer. Often referred to as the "Princess of Pop", she is credited with influencing the revival of teen pop during the late 1990s and early 2000s. Spears has sold over 150 million records worldwide, making her one of the world's best-selling music artists. She has earned numerous awards and accolades, including a Grammy Award, 15 Guinness world records, six MTV Video Music Awards, seven Billboard Music Awards, the inaugural Radio Disney Icon Award, and a star on the Hollywood Walk of Fame. Her heavily choreographed music videos earned her the Michael Jackson Video Vanguard Award.