Kim Hyo-jin began her entertainment career as a model before making her acting debut in the 1999 SBS omnibus series 8 Love Stories. In 2000, she appeared in several television dramas such as MBC’s All About Eve and KBS2’s RNA. Her performance in the latter won her Best New Actress at the KBS Drama Awards. Her career breakthrough came in 2004 when she starred in the sex comedy film Everybody Has Secrets, which scored her the Best New Actress trophy at that year’s Golden Cinematography Awards. In 2008, she headlined the SBS family drama I Am Happy. In 2009, she made her theater debut in the play A Midsummer Night’s Dream. In 2010, she starred alongside Kim Kkot-bi in the queer film Ashamed. In 2012, she became part of the erotic thriller film The Taste of Money, which earned her a Best Supporting Actress nomination at the 21st Buil Film Awards. In 2013, she was cast in another lesbian role in the film My End Is My Beginning. In 2020 and 2021, she joined the main casts of Private Lives and Human Disqualification, which both aired on JTBC.

Kim Hyo-jin married actor-director Yoo Ji-tae in December 2011. They are both passionate about volunteering, particularly for World Vision. They have two sons together.