Fifth Harmony, often shortened to 5H, is an American girl group based in Miami, composed of Ally Brooke, Normani, Dinah Jane, Lauren Jauregui, and formerly Camila Cabello until her departure from the group in December 2016. The group signed a joint record deal with Simon Cowell's label Syco Records and L.A. Reid's label Epic Records after forming and were the last contestant eliminated in the second season of the American singing competition series The X Factor in 2012.

The group released their debut single "Miss Movin' On", preceding their extended play Better Together. In 2015, The group released their debut studio album Reflection, which was certified gold by the Recording Industry Association of America (RIAA). It spawned the singles "Boss", "Sledgehammer" and "Worth It"; the latter of which was certified triple platinum by RIAA, and reached the top ten in thirteen countries. In 2016, the group released "Work from Home", the lead single from their second album 7/27, which peaked at number four on the Billboard Hot 100, making it the first top five single by a girl group in a decade on that chart. They released their self-titled third album in 2017. The group went on indefinite hiatus in March 2018, allowing its members to pursue solo projects.

Fifth Harmony has sold nearly 15 million RIAA certified units, and are one of the best-selling girl groups of all time with a reported 33 million copies sold. They are known for their vocal range and songs with themes of female empowerment, self positivity, confidence, and unity. As of 2016, they have earned 1.6 billion on-demand streams, according to Nielsen SoundScan. Billboard named them the biggest girl group of the 2010s. In 2017, Time referred to them as arguably "the biggest girl group in the world".

Fifth Harmony have earned the most top ten albums on the U.S. Billboard 200 for any girl group in the 21st century. Their accolades include an American Music Award, three MTV Europe Music Awards, three Guinness World Records, four MTV Video Music Awards, four iHeartRadio Music Awards, the first ever Billboard Women in Music Group of the Year award, a record five Nickelodeon Kids' Choice Awards (the most for a girl group), and ten Teen Choice Awards.