Lee Min-jung began acting on stage, particularly in Jang Jin’s plays. Her career breakthrough came in 2009 when she appeared in the hit KBS2 series Boys Before Flowers. That same year, she was cast in her first screen leading role in the SBS weekend drama Smile, which won her the New Star Award at the SBS Drama Awards. In 2010, she starred in the romantic comedy film Cyrano Agency, which earned her multiple Best New Actress trophies. In 2011, she acted alongside Jang Hyuk and Kim Hee-ae in the SBS drama Midas. She was then paired with Gong Yoo in the 2012 KBS2 body-swap rom-com Big. In 2014, she and Joo Sang-wook played a divorced couple in MBC’s Sly and Single Again. They reunited four years later for the SBS romance melo Fate and Wrath. In 2020, she joined the well-received KBS2 family drama Once Again, which gave her Top Excellence Awards at the KBS Drama Awards and the APAN Star Awards.

Lee Min-jung studied theater at Sungkyunkwan University. She is the granddaughter of the late renowned painter Park No-soo. In August 2010, she tied the know with actor Lee Byung-heon. They welcomed their son on March 31, 2015.