Girl's Day (걸스데이) is a South Korean all-girl quartet signed with DreamTea Entertainment. Initially gaining public interest performing dance flash mobs in the streets of Seoul, they debuted in July 2010 with the release of their first song, "갸우뚱", an electro-pop song. The current lineup is made up of Sojin (소진), Minah (민아), Yura (유라), and Hyeri (혜리).

In September 2010, it was announced that two members of the original lineup, Ji Sun and Ji In, would be leaving to pursue other activities. They would soon be replaced by two new members, Yura and Hyeri. The new lineup was showcased with the release of their second lead single, "잘해줘봐야", marking a depature from the autotune-heavy "cute" pop they debuted with and showing off a mature dance-pop sound.

In early 2011, they collaborated with Japanese artist Nami Tamaki (玉置成実) on her song "Girlie Night". In March 2011, they released their third lead single, "반짝반짝", thrusting them further into popularity.

In October 2012, it was announced that member Jihae left the group to pursue her education at the Sungkyunkwan University. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.