IU debuted as a singer in 2008 with the extended play Lost and Found. In 2009, she released her debut studio album Growing Up, which brought her mainstream success. Her career breakthrough came in 2010 when she dropped her third extended play Real featuring the lead single Good Day, which dominated the Gaon Digital Chart for five consecutive weeks. In 2013, she released her third full-length album Modern Times, which placed second on Billboard’s “25 Greatest K-Pop Albums of the 2010s” list. In 2015, she released her self-composed extended play Chat-Shire, with Twenty-Three serving as its lead single. Her popularity landed her on Forbes Korea’s Power Celebrity list multiple times, peaking at number 3 in 2012. She was also named Gallup Korea’s Singer of the Year in 2014 and 2017.

IU made her acting debut in the hit 2011 KBS2 series Dream High. In 2013, she won Best New Actress at the KBS Drama Awards for her leading roles in You’re the Best, Lee Soon-shin and Pretty Man. In 2015, she joined the main cast of the KBS2 drama The Producers, which earned her two Excellence Award nominations. In 2016, she acted alongside Lee Jun-ki in the SBS fusion sageuk series Moon Lovers: Scarlet Heart Ryeo. In 2019, she starred in the tvN drama My Ajusshi, which scored her a Best Actress nomination at the 55th Baeksang Arts Awards. In 2020, she was once again nominated for the Baeksang Best Actress trophy for her work in the hit tvN dark fantasy drama Hotel del Luna.

IU’s stage name means “I” and “You”. She dated indie singer Jang Kiha for four years. She is best friends with actress Yoo Inna and has a younger brother named Lee Jong-hoon.