Fifth Harmony, often shortened to 5H, were 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 an indefinite hiatus in May 2018, allowing its members to pursue solo projects, with a one-off reunion performance in 2025.

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.

Career 2012: The X Factor

In 2012, Ally Brooke, Camila Cabello, Normani Kordei, Dinah Jane and Lauren Jauregui auditioned as soloists on the second season of the American televised singing competition The X Factor. The latter four failed to progress in the "Teens" category, with Brooke failing to enter the "Young Adults" category. However, they were later brought back and put together to form a five-piece girl group at The Fillmore, in Miami, Florida on July 27, thus qualifying for the "Groups" category. Judges Demi Lovato, L.A. Reid, Britney Spears and Simon Cowell helped form the group. For their qualifying song at the "judges' houses", and their first song as a group, the girls sang an acoustic version of "Impossible" by Shontelle. Afterwards, Marc Anthony called the performance "unbelievable" with Cowell sharing similar sentiments saying that they were "clearly one great group". Initially, the group's name was "Lylas" (an acronym for Love You Like a Sister), but another group called "The Lylas" (which consists of four of Bruno Mars' sisters) claimed that the show stole their name. Thereafter, Lylas changed their name to 1432 (a colloquial term for I Love You Too), which was announced on the first live show on October 31, during which 1432 performed "We Are Never Ever Getting Back Together" by Taylor Swift. Cowell and Reid were critical of the new name, and Cowell suggested that the group be renamed again. During the first live results show on November 1, 1432 performed "Skyscraper" by Demi Lovato in a sing-off with three-piece girl group Sister C. Cowell decided to send 1432 through to the Top 12 and announced that they would be renamed via the viewers online. The name chosen by the public was announced: "Fifth Harmony".

In the semi-finals stage of the show, the group performed Ellie Goulding's "Anything Could Happen" as well as "Impossible" for the second time during the competition. However, their performance of "Impossible" received mostly negative reviews from the judges because the group had previously performed the song at Cowell's home (although not on The X Factor concert stage). Three members of the group (Camila, Lauren, and Ally) sang parts of the song in fluent Spanish. The following night's public vote results advanced Fifth Harmony to the final three along with Tate Stevens and Carly Rose Sonenclar. On the Top three live show, Fifth Harmony performed "Anything Could Happen" for the second time as their "Song of the Series" song. Their second song was a duet with The X Factor judge Demi Lovato singing "Give Your Heart a Break". Their final song of the night (and their last on the show) was "Let It Be" by the Beatles, billed as their "$5 million song". After the first round of the finals, they did not receive enough votes from the public to advance to the Top two on December 20, 2012.

The X Factor performances and resultsShowThemeSongOrderResultDinah Jane HansenLauren JaureguiAlly BrookeNormani HamiltonCamila CabelloAuditionsFree choice"If I Were a Boy""If I Ain't Got You""On My Knees""Chain of Fools""Respect"rowspan="5" Through to bootcampBootcamp 1Free choice"Hero""E.T.""Somebody That I Used to Know""If I Ain't Got You""Back to Black"Through to bootcamp 2Bootcamp 2Group performanceNot airedThrough to bootcamp 3Bootcamp 3Duet performance"Stronger (What Doesn't Kill You)" (with Diamond White)"These Arms of Mine" (with Sister C)"Knockin' on Heaven's Door" (with Julia Bullock)"What Makes You Beautiful" (with Arin Ray)"Your Song" (with Jordan Shane)Regrouped/through to judges' housesJudges' housesFree choice"Impossible"Through to live showsWeek 1Made in America"We Are Never Ever Getting Back Together"13Bottom twoSing-off"Skyscraper"8Saved by Simon CowellWeek 2Songs from Movies"A Thousand Years"13Safe (5th)Week 3Divas"Hero"8Safe (6th)Week 4Giving Thanks"I'll Stand by You"6Safe (7th)Week 5Number-ones"Stronger (What Doesn't Kill You)"4Safe (4th)Week 6Unplugged"Set Fire to the Rain"4Bottom threePepsi Challenge songs"Give Your Heart a Break"10Final Showdown (Week 6) Free choice"Anytime You Need a Friend"1Saved by judges' vote (4th)Semi-finalContestant's choice"Anything Could Happen"4Safe (2nd)No theme"Impossible"8FinalFavourite performance"Anything Could Happen"3 EliminatedCelebrity duet"Give Your Heart a Break" (with Demi Lovato)6Winner's song"Let It Be"9Christmas song"Christmas (Baby Please Come Home)"2

2013–2014: Better Together

Approximately a month following The X Factor season two finale, on January 17, 2013, Fifth Harmony was officially signed by their mentor Simon Cowell to his record label, Syco Music, in a joint deal with fellow judge L.A. Reid's label, Epic Records. Popdust awarded them the "Next Pop Superstar of 2013" recognition, an annual competition held for rising artists. They began recording covers of songs which were uploaded on the video sharing platform, YouTube. Three of their covers received public praise from the original artists, including Ed Sheeran, Ariana Grande and Mikky Ekko. Fifth Harmony was also featured on Boyce Avenue's extended play, Cover Collaborations, Volume 2, singing covers of "Mirrors" by Justin Timberlake and "When I Was Your Man" by Bruno Mars.

Their debut single "Miss Movin' On" was released on July 16, 2013, as the lead from their debut EP and peaked on the Billboard Hot 100 at number 76, formerly the highest-charting single from an X Factor contestant to appear on the chart. Their debut extended play Better Together was released on October 22, selling 28,000 copies in its first week and peaking on the Billboard 200 at number six. Spanish versions of the EP, Juntos and Juntos Acoustic were released on peaking at number two and 12, respectively on the Billboard Top Latin Albums chart. The song was certified gold in the United States for selling 500,000 digital downloads and streams combined. The extended play's promotional single, "Me & My Girls" charted on the Billboard Hot Digital Songs chart at 53.

Throughout July and August 2013, Fifth Harmony performed at various shopping malls across the United States in a promotional tour titled Harmonize America. On August 5, 2013, the girl group celebrated their one-year anniversary by performing five shows in New York City. The pop-up concerts throughout the city included performances at the iHeartRadio Theater and Madison Square Park. The group was one of the opening acts for Cher Lloyd during her I Wish Tour which started on September 6, 2013. On September 11, 2013, the group announced their debut concert tour, playing in concert halls in Canada and the United States. Their opening act was indie pop band AJR. On November 24, they performed "Better Together" on the red carpet at the 2013 American Music Awards. They supported Demi Lovato's Neon Lights Tour as one of three opening acts playing 27 arenas across North America.

2014–2015: Reflection and breakthrough

On January 23, 2014, Fifth Harmony headlined the MTV Artists to Watch concert, an annual concert which showcases breakout artists that will be promoted by MTV during the year. The concert also featured performances by Tori Kelly, Rixton, Echosmith and Jake Miller. In early 2014, Fifth Harmony confirmed reports that recording had begun for their full-length debut album with record producers Julian Bunetta, Daylight, Joe London, and multi-instrumentalist songwriter Ricky Reed. The group stated the album is less pop, "more rhythmic" and has a more mature sound than Better Together. Fifth Harmony's third concert tour was revealed at the end of March 2014, titled Fifth Times a Charm Tour, with dates in Puerto Rico and the United States.

The album's lead single, "Boss", was released on July 7, 2014, peaked at number 43 on the Billboard Hot 100 chart with first-week sales of 75,000, and received a platinum certification by the United States for selling a million digital downloads and streams combined. The second single from Reflection, the Meghan Trainor-penned "Sledgehammer", was released on October 28, 2014, and went on to become the group's first top 40 entry on the Billboard Hot 100, and was also certified platinum in the United States. On December 4, 2014, the group was invited to sing at the White House for the National Christmas Tree Lighting, where they performed a cover of Mariah Carey's hit Christmas song, "All I Want for Christmas Is You". It was announced by Billboard that a representative from Epic Records had confirmed that the album release was moved from December 16, 2014, to January 27, 2015.