洁西卡‧艾伦‧柯妮许（英文：Jessica Ellen Cornish；1988年3月27日－），英国歌手和词曲作者，她的艺名Jessie J更广为人知，在英国伦敦出生长大。她在为贾斯汀·汀布莱克、艾丽西亚·凯斯和克里斯蒂娜·阿奎莱拉等人写出成名曲后，开始受到关注。2011年她赢得了全英音乐奖。其特色为流畅的一字多转音及高亢具有爆发力的嗓音，是一位能够巧妙运用声音的女歌手，拥有横跨三个八度的音域。
Jessie J与隶属环球唱片的环球共和唱片公司签约后，推出了首支个人单曲 "Do It Like a Dude"，并登上英国单曲排行榜的第二名。2011年，Jessie J陆续登上包括英国、法国、爱尔兰及新西兰等十九个国家的排行榜冠军，在此之后，她便以"Price Tag"为主打，推出了首张专辑《你是谁》（Who You Are），该年3月、4月分别在英国与美国发行。
2016年为美国喜剧动画电影“冰川时代:笑星撞地球”中的Brooke配音。
1988年3月27日，Jessie J在英国伦敦东部的查德威尔希思（Chadwell Heath）出生，高中就读于红桥伦敦自治市梅菲尔德高中。她曾至柯林表演艺术学校进修，当时的她被选派演出十一年历史的音乐剧《微风轻哨》，该剧由安德鲁·洛伊·韦伯在伦敦西区剧院完成。
2003年，Jessie J十五岁时，她赢得了电视秀英国杰出天才大赛中“最佳流行歌手”的奖项。16岁时，开始就读英国伦敦表演艺术学校（The BRIT School）。并在17岁加入一个女子团体灵魂深处（Soul Deep）。2006年，与阿黛尔 及里欧娜同年毕业于表演艺术学校。
Jessie J罹患沃夫巴金森怀特症候群，为一种先天心律不整的疾病，她称她曾在18岁得过一次小中风。
她和Gut唱片公司签约，公司准备为她录制专辑，但发布前公司倒闭了。后来她发现作为一位作曲家比较创佳绩，获得了索尼ATV的出版合同。她与麦莉·赛勒斯的"Party in the USA"的制片 Dr.Luke一起合写这首歌歌词,还和Claude Kelly（克劳德凯利）合作，以及为贾斯汀‧提姆布莱克，克里斯·布朗（与他欧洲巡回演出），艾莉西亚‧凯斯，克莉丝汀‧阿奎莱拉写词曲。她的歌曲"Sexy Silk"被喜剧电影Easy A当成配乐。
Jessie J在2010年11月21日于英国发行她的单曲"Do It Like A Dude"，该单曲于25日首次出现在英国单曲排行榜，而后达到最顶峰排在第二位。2010年12月15日她宣布已经赢得2011年全英音乐奖的评论家选择奖。2010年12月6日英国广播公司宣布她已获选为2011年年度之声人物（Sound of 2011）。2011年1月7日，她被宣布为获胜者歌手名单其中之一，其中包括詹姆斯·布雷克、The Vaccines、Jamie Woon和Clare Maguire。她的首张专辑《你是谁》（Who You Are）将在英国于2011年3月28日公布美国则在4月12日，一个叫《Later...with Jools Holland》的音乐节目在11月9日推广"Price Tag"。这首发行歌曲为专辑的第二首单曲，有和美国说唱歌手B.O.B合作，在2011年1月28日发布。
2012年，她与皇后乐队在伦敦奥运会闭幕式上演唱《We Will Rock You》一曲。
2014年，因为想把传媒焦点集中在她的工作，她移居至洛杉矶。
Jessie J在接受采访时透露，她希望与妮琪·米娜合作。（后来妮琪·米娜说她爱上了Jessie J ，说：她出来和我聚餐后，就爱上她说话的语气与一切。）Jessie J在接受采访时说她的专辑有不同的音乐流派。她说：比如像 "Do It Like a Dude" 是有关男性自尊心在音乐界。她还表示在说她的首张专辑将包括雷鬼、嘻哈、舞蹈和R＆B。她已计划英国巡回演出，目前有七个确定日期。
2018年Jessie J继上张专辑（Sweet Talker） 睽违四年于5/25发布全新专辑（R.O.S.E），并将专辑分成四个部分，R（Realisations/领悟）、O（Obsession/沉迷）、S（Sex/性）、E（Empowerment/释放）。
On 25 February 2011 her debut album, , was released. The album first entered the UK Albums Chart on 6 March 2011 where it charted at number two. The album charted into the top ten in a number of countries and number 11 in the US. After the release she went on to release a third single from the album, "Nobody's Perfect". MTV reported that the single is, so far, only confirmed for release in the United Kingdom. The album's fourth single was "Who's Laughing Now". "Domino" was her second US single. The Dr. Luke-produced track was sent to mainstream radio on 6 September 2011. With the success of in North America, Jessie was chosen to tour as the opening act for American pop artist Katy Perry's in 2011 but pulled out after breaking her foot in rehearsals.Jessie J served as the house artist at the 2011 MTV Video Music Awards, performing several of her original songs along with covers around commercial breaks.
On 12 June 2011, at the Summertime Ball held at Wembley Stadium,Jessie ruptured several tendons in her foot during rehearsals, and performed her set the following day while sitting on a gilded throne. For her appearance at Glastonbury Festival 2011 on 25 June 2011, she performed on the throne again, stating that her doctor had told her not to perform with her broken foot which would take six weeks to heal. Jessie J was scheduled to play at several festivals throughout the summer, however it was reported on 1 July 2011 that she would not be able to attend T in the Park, T4 on the Beach, Wembley:Orange, iTunes Festival, Lovebox, and Oxegen due to the injuries to her foot. Her record label released an official statement on 30 June 2011 that under strict orders from her doctor, she would not be able to perform for a number of weeks so that she could recuperate properly. She returned to the concert circuit in late August, including sets at the V Festival and The Big Chill. At the 2011 MTV VMA's she was still in a cast and using the throne.
James Morrison's third studio album, features a collaboration with Jessie J called "Up", the song was released as a single on 16 November 2011. Jessie J re-released on 9 November 2011, featuring the regular tracks plus "Domino". "Domino" topped the UK charts and became her first top 10 hit in the US, following the success of "Price Tag". While in Australia for the Oceania leg of her tour in support of , an interview on a TV talk show ended with her being sawed in half by magician Sam Powers in his thin model sawing illusion. At the 2012 Brit Awards on 21 February, Jessie J received two Brit Award nominations, Best British Female Artist, and Best British Single ("Price Tag").
With featured artist, Jessie J released the sixth single,"Laserlight", from her debut album on 4 May 2012.In the United Kingdom,the song debuted at number twenty-six on the UK Singles Chart on the chart issue dated 21 April 2012. The following week the song climbed twenty-one positions to number five, making it her sixth top ten single from one album. With the charting success, she became the first UK female solo artist to achieve six top-ten singles from a single studio album. The achievement was compared with 嘎嘎小姐, Katy Perry, Michael Jackson and boy band Take That, recording artists who previously broke the same record.
On 4 June 2012, Jessie appeared at the Diamond Jubilee Concert for Queen Elizabeth II, performing a duet with will.i.am. Together, they performed "I Gotta Feeling", a song she previously recorded with the other four coaches of the televised singing competition, . She later sang her international hit, "Domino". On 12 August 2012 she performed "Price Tag", "Written in the Stars", "Dynamite", and "You Should Be Dancing" with Tinie Tempah and Taio Cruz, and "We Will Rock You" with Queen at the Closing Ceremony of the 2012 Olympic Games in London. Jessie J was a coach on the BBC One programme for its first two series in 2012 and 2013.
On 31 January 2012, Jessie J announced that she had begun recording her second studio album. She also stated that she hoped to collaborate with many artists that year, possibly including some of her fellow coaches on . It was revealed that she worked in the studio with CeeLo Green after he contacted her on Twitter. Jessie has also revealed on Twitter that she worked with Diane Warren and co-author of her song "Price Tag", Claude Kelly.
Via microblogging website Twitter, Jessie J announced her first arena tour, called Nice to Meet You Tour (later renamed Alive Tour due to the release of her second studio album titled ), which began on 15 October 2013 and concluded on 8 February 2014. "Wild" was released as the lead single from and was a top 5 hit in both the United Kingdom and Australia. Other singles released from the album included "It's My Party" and "Thunder". Jessie also featured on DJ Cassidy's debut single "Calling All Hearts", along with Canadian singer Robin Thicke.
Her third studio album was released on 13 October 2014 in the UK, where it peaked at number 5. "Bang Bang" recorded with Ariana Grande and Nicki Minaj serves as the first single from the album. The song reached number one on the UK Singles Chart, becoming her third number one and seventh top five single in the UK. "Bang Bang" debuted on the US Hot 100 at number 6, making it the second highest new entry of 2014 on the chart. The song became Jessie J's second top 10 single in the US, after her previous single "Domino", and eventually peaked at number 3. In 2015, she became the judge and mentor of . In the nominations for the 2016 Brit Awards, Jessie J's 2015 single "Flashlight" (from the soundtrack to the film ) was among the nominees for Best British Video. In January 2015 she began the Sweet Talker Tour to promote the album.
Jessie J joined the cast of voices for singing the movie's theme song "My Superstar" (written by Alexander Geringas and Nikki Leonti) featuring Tha Vill. The song was eventually not released as a single and was not included in the soundtrack.
On 11 August 2017, Jessie J released a new single, "Real Deal", for M&M's advertising campaign. On 12 September, she announced her fourth album and the single "Think About That", which was released on 15 September 2017 as the album's lead single. Four further songs from were then released, with "Think About That" representing realisation. "Not My Ex", was released as its second single on 6 October 2017 and represents obsession and the third single "Queen" was released on 17 November 2017, representing empowerment. In October 2017, Jessie J began her R.O.S.E. tour across Europe and the US to promote the upcoming album.
In January 2018, she appeared on the sixth season of the Chinese singing competition and won the show three months later as the first international winner ever, with almost half of the total votes from the Chinese audience. She also set a record by winning 5 rounds, with 3 rounds won in a row leading to the finals. She also set the record for highest average rank (1.5), having never fallen out of top 3 in every round competed (avoided repêchage challenges as she was never eliminated). In January 2018.
In May 2018 her fourth studio album was released. The album was released as four EPs titled Realisations, Obsessions, Sex, and Empowerment, creating an acronym for "R.O.S.E." The album moved away from the pop sound heard in much of her past music, instead taking on an R&B style. In September 2018, Jessie J announced her first Christmas album titled , which was released on 26 October 2018. In December 2018, Jessie J confirmed that she would be appearing as a coach on alongside Pixie Lott, Danny Jones and will.i.am for its third series. She also stated in an Instagram Live that she wants to write new pop/soul songs. In April 2019 Jessie began touring festivals across Europe and Asia. She announced via instagram that the tour is called , in honor of her close friend / bodyguard Dave Last "Lasty" who died in December 2018.Jessie J has appeared on the major UK charity telethons, Children in Need and Comic Relief.She confirmed on 2 August 2011 that she would be shaving her hair off for charity in 2012. Speaking via her official Twitter account she said: "It's hair, It will grow back. Even if it takes 2 years,studio if it saves lives. Even if its 1 life that's something."Her career began when she met record producers Starsmith and Frankmusik, and she was later spotted by Jamie Lillywhite. On 15 March 2013, Jessie's head was shaved live during.