Lee Ji-eun (born May 16, 1993), professionally known as IU, is a South Korean singer, songwriter and actress. While still in middle school, IU auditioned for various talent agencies with ambitions of becoming a singer. She signed with Kakao M (formerly LOEN Entertainment) in 2007 as a trainee and began her music career at the age of 15 with her debut album, Lost and Found. Her follow-up albums, Growing Up and IU...IM, brought her mainstream success, but it was through "Good Day" (Korean: 좋은 날), the lead single from her 2010 album Real, that she achieved national stardom. "Good Day" spent five consecutive weeks at the top position of South Korea's Gaon Digital Chart, a joint record along with Psy's "Gangnam Style".
With the success of her 2011 albums, Real+ and Last Fantasy, IU established herself as a formidable force on the music charts of her native country and further cemented her girl next door image as Korea's "little sister". 2011 also saw her first foray into song-writing with "Hold My Hand", which was written for the television series The Greatest Love. IU's third full-length album release, Modern Times (2013), showcased a more mature style that was a departure from her established girlish image, with several tracks reaching the top 10 positions on Gaon Digital Chart. While her subsequent releases, including albums A Flower Bookmark, Chat-Shire, and Palette continued to deviate from the mainstream K-pop style, IU retained her dominance on music charts. Chat-Shire marked the first time she is credited as the sole lyricist and producer of her own album.
IU has released four studio albums and nine extended plays, scoring three number-one albums and eighteen number-one singles on the Gaon Music Charts. As one of the best-selling solo artists in the K-pop industry, which is dominated by boy and girl groups, she has been included on Forbes magazine's annual Korea Power Celebrity list since 2012, reaching a peak ranking of number three in 2012. Billboard recognized IU as the all-time leader of its Korea K-Pop Hot 100 chart with the most number-one songs and the artist who has held the number-one position for the most number of weeks. According to a Gallup Korea survey, she was the most popular idol and artist among South Koreans in 2017.
Aside from her music career, IU has also ventured into hosting radio and television shows, as well as acting. Following her supporting role in teen drama Dream High and minor appearances in several television series, IU starred in You're the Best, Lee Soon-shin, Pretty Man, The Producers, Moon Lovers: Scarlet Heart Ryeo and My Mister.
She is also known as Lee Ji-eun, 아이유, Lee Ji Eun, Lee Jieun, Lee Jee-eun, Lee Jee Eun, 이지은 and 이 지은.