Nam Ji-hyun debuted as a child actress in the 2004 MBC series Say You Love Me. Her early notable works include MBC’s East of Eden and Queen Seon-deok, where she played the young counterparts of Han Ji-hye and Lee Yo-won’s characters, respectively. Her performance in both dramas won her the Best Young Actress honors at the 2008 and 2009 MBC Drama Awards. In 2011, she appeared in the film A Reason to Live, which gave her a Best New Actress nomination at the 21st Buil Film Awards. In 2013, she received another Best New Actress nomination at the 34th Blue Dragon Film Awards for the action film Hwayi: A Monster Boy. She then joined the 2014 KBS2 drama What’s With This Family, which earned her the Best New Actress trophy at the KBS Drama Awards. In 2016, she took on her first leading role in the MBC romantic comedy Shopping King Louis, opposite Seo In-guk. In 2017, she bagged an Excellence Award at the SBS Drama Awards for the series Suspicious Partner. In 2018, she was paired with D.O. in the hit tvN sageuk 100 Days My Prince. In 2020, she starred in the MBC fantasy mystery-thriller 365: Repeat the Year, which scored her a Top Excellence Award at the MBC Drama Awards.

Nam Ji-hyun majored in psychology at Sogang University.