Jellyfish Entertainment 젤리피쉬엔터테인먼트 was founded by composer-producer Hwang Sejun in Seoul on August 17, 2007.
The company's first artist was Sung Sikyung, an already established ballad singer. A year later, the company signed Lisa and Park Hakki.
In November 2008, singer Park Hyoshin signed to the agency and was featured on the album Hwang Project Vol.1 Welcome to the Fantastic World. In 2009, "Super Star K" contestant Seo Inguk and Altair (Lee Jihoon) joined Jellyfish, too.
In December 2010, Jellyfish's artists collaborated for the Jelly Christmas holiday album project with the lead single "Christmas Time." In December 2011, Sung Sikyung, Fly to the Sky's Brian Joo, Seo Inguk, Park Hakki, Park Janghyun and Hwang Project collaborated again for Jelly Christmas with the single "Christmas for All."
In April 2012, Jellyfish Entertainment formed a male idol group on "MyDOL," a competition survival show that aired on Mnet. The winners debuted as VIXX on May 24, 2012.
In June that year, Lee Seokhoon of SG Wannabe released the digital single "The Beginning of Love." The song was part of CEO Hwang Sejun's Y.Bird from Jellyfish Island project, a series of periodically released single albums designed to showcase the different sides of Jyllyfish's artists to the public. On September 12, Jellyfish held their first live concert, Jellyfish Live, at Tokyo's Zepp Diver City in Japan. In December, both Park Hyoshin and Sung Sikyung held concert performances in Seoul. Jellyfish's artists collaborated again for the Jelly Christmas 2012 Heart Project with the single “Because It's Christmas.” Proceeds from the project were donated to The Salvation Army Korea.
In 2013, the Y.Bird from Jellyfish Island project released the digital singles "I Can't Live Because of You" by Seo Inguk featuring Verbal Jint in February and "Girl’s Why?" by VIXX and indie duo OKDAL in October.
In December 2013, 19% of Jellyfish's shares was acquired by their distributor, CJ E&M, as they formed a strategic alliance with the distributor.
In July 2015, "K-pop Star 4" contestant Park Yoonha signed an exclusive contract with Jellyfish Entertainment. The following month, VIXX's Ravi and Leo formed the sub-unit VIXX LR. The Jelly Christmas 2015 EP was released on December 15 with the single “Love in the Air 사랑난로." Seo Inguk, VIXX, former Jewelry member Park Jungah, and Park Yoonha all featured in the EP.
In the first half of 2016, Jellyfish trainees Kim Nayoung, Kang Mina, and Kim Sejeong represented Jellyfish Entertainment in the television survival show "Produce 101." After winning the show, Mina and Sejeong debuted in the year-long project girl group I.O.I., while still under Jellyfish Entertainment. It was confirmed that following their promotions as part of I.O.I., the trainees would officially debut as members of the agency's first girl group.
On June 3, 2016, Jellyfish Entertainment announced the launch of their new music channel Jelly Box. Similar to Y.Bird from Jellyfish Island, Jelly Box showcases Jellyfish Entertainment artists and producers and includes collaborations with artists outside of the label.
On June 28, 2016, Jellyfish debuted nine-member girl group Gugudan.
In August 2016, Park Hyoshin departed from the agency after eight years.
In October 2016, former Dal Shabet member Jiyul signed a contract with the agency to pursue her career as an actress.
In November 2016, former Jewelry member Kim Yewon joined Jellyfish Entertainment as an actress.
On December 13, 2016, Jellyfish Entertainment released their Jelly Christmas 2016 single album featuring the song "Falling" 니가 내려와 as part of both their annual Christmas albums and their digital music channel project Jelly Box. The Jellyfish artists participating were Seo Inguk, VIXX, Gugudan, Park Yoonha, Park Jungah, Kim Gyusun, Kim Yewon, and Jiyul.
In April 2017, agency trainee Yun Heeseok represented Jellyfish Entertainment in the second season of the television survival show "Produce 101."
On April 10, 2017, actress Cho Hyejung joined Jellyfish Entertainment.
In June 2017, actress Jung Somin joined Jellyfish Entertainment.
On July 19, 2017, Jellyfish Entertainment announced that the two youngest members of Gugudan, Kang Mina and Cho Hyeyeon, were set to debut as a sub unit in August. The unit, Gugudan 5959, made its debut on August 10 with digital single "Ice Chu."
On August 16, 2017, indie soloist Jang Hyejin joined Jellyfish Entertainment.
In November 2017, it was announced that in August, CJ E&M had become the label's largest shareholder after having 50% (19% acquired in 2013 and 32% acquired in 2017) of Jellyfish's shares.