Im Soo-jung started her entertainment career as a model for teen magazines before making her debut as an actress in the KBS2 series School 4 in 2001. Her career breakthrough came in 2003 when she was cast in a leading role in director Kim Jee-woon’s horror movie A Tale of Two Sisters. Her work in the film won her numerous acting awards, including Best New Actress at the 24th Blue Dragon Film Awards and Best Actress at the 24th Fantasporto Film Festival. In 2004, she starred in the hit KBS2 series I’m Sorry, I Love You, opposite So Ji-sub. She won Best New Actress at the KBS Drama Awards for her performance in the drama. In 2006, she appeared in director Park Chan-wook’s romantic comedy film I’m a Cyborg, But That’s OK, which earned her several Best Actress nominations. In 2007 and 2008, she scored another set of Best Actress nominations for the movie Happiness. In 2012, she acted alongside Lee Sung-kyun and Ryu Seung-ryong in the romantic comedy film All About My Wife, in which she was named Best Actress at the 13th Women in Film Korea Awards and the 33rd Blue Dragon Film Awards. In 2019, she was nominated for a Top Excellence Award at the 12th Korea Drama Awards for the tvN series Search Query: WWW.

In 2015, Im Soo-jung started a vegan diet after discovering that she is allergic to animal proteins.