Secret (Korean: 시크릿) is a four-member South Korean girl group formed in 2009. The group consisted of Jeon Hyosung, Jung Hana, Song Jieun and Han Sunhwa. The group were signed under LOEN Entertainment and released their debut single, "I Want You Back", in 2009.In 2010 they released two mini albums entitled Secret Time with the lead single "Magic" and Madonna. In January 6, 2011, Secret released their third mini album entitled Shy Boy. The lead single "Shy Boy" garnered much success for the group reaching number 1 on Inkigayo, M! Countdown and on Music Bank for three consecutive weeks. By the end of February 2011, the group closed all their promotion for "Shy Boy" despite the ongoing success of the song, to make way for the official debut of Ji Eun with her single “Going Crazy, a collaboration with Korean rapper Bang Yong Guk. The group had a short hiatus by spring and in mid 2011 they returned with another success for "Starlight Moonlight".

In late 2011, the group made their official debut in Japan. Initial reactions for the group were positive and they performed on various Japanese shows for promotion. "Madonna" was chosen as their first official single in Japan with an accompanying mini-album. The mini-album proved to be a success in Japan debuting at the top 10 on Oricon charts, landing at number 9. Secret was one of the first three Korean girl groups to debut at the top 10 on the Oricon album charts, the others were SNSD and Kara being the 1st and 2nd respectively. Aside from their commercial accomplishments, the group is well known for their cute and girl next door image through their post-2011 songs after displaying a sexy image on their debut period back in 2010.

Jeon Hyosung (Hangul: 전효성), the leader, lead vocalist and main dancer of the group, was born on October 13, 1989. Hyosung was originally set to debut as the maknae of girl group Five Girls (오소녀) under Good Entertainment, along with Wonder Girls’ Yubin, After School’s UEE, G.NA and former T-ara member and actress Yang Jiwon.

Jung Hana (Hangul: 정하나), better known as her stage name Zinger, is the main rapper and vocalist of the group. Zinger was born on February 2, 1990.

Song Jieun (Hangul: 송지은), is the main vocalist of the group. She was born on May 5, 1990.

Han Sunhwa (Hangul: 한선화), the maknae and vocalist of the group, was born on October 6, 1990.