Lee Joo-yeon debuted with the South Korean girl group After School in 2009 with the song AH! from their debut single album New Schoolgirl. In 2010, they won the K-Pop New Artist of the Year 2009 at the Billboard Japan Music Awards. Also in 2010, they took home the Best Newcomer Award at the Seoul Music Awards. In 2011, they released their debut and only Korean studio album called Virgin, which featured 13 songs. Lee Joo-yeon left the group in 2015.

Prior to her debut as an idol, Lee Joo-yeon landed a cameo appearance in the 2007 romantic comedy film My Tutor Friend 2. In 2010, she officially made her acting debut in the KBS1 daily drama Smile, Dong-hae. In 2014, she became part of A New Leaf and Hotel King, which both aired on MBC. In 2017, she joined the main cast of the MBC family drama Sisters-in-Law. In 2018, she acted alongside Choi Jin-hyuk and Song Ha-yoon in MBN’s Devilish Joy. In 2020, she played a supporting role in the SBS legal drama Hyena.

Lee Joo-yeon attended Dongduk Women’s University.