"1999" is a song by English singer Charli XCX and Australian singer Troye Sivan, released as the lead single from the former's third studio album Charli on 5 October 2018. The single cover was inspired by the 1999 film The Matrix. It follows several singles released earlier in 2018 by Charli XCX and Sivan's 2018 album Bloom. The track reached number 13 on the UK Singles Chart dated 22 November 2018, becoming Charli XCX's tenth top 40 single and first top 15 single since 2015, as well as Sivan's fourth top 40 single and his first top 20 single.

Charlotte Emma Aitchison, known professionally as Charli XCX, is an English singer and songwriter. Born in Cambridge and raised in Start Hill, Essex, she began posting songs on Myspace in 2008, which led to her discovery by a promoter who invited her to perform at warehouse raves. In 2010, she signed a recording contract with Asylum Records, releasing a series of singles and mixtapes throughout 2011 and 2012.