Lee Kyoung-mi was born in Seoul, and graduated with a Russian degree from Hankuk University of Foreign Studies.

After working at a company for three years, she entered the School of Film, TV & Multimedia of the Korea National University of Arts, graduating with a major in Filmmaking in 2004.

Lee made her feature directorial debut with Crush and Blush (2008), a black comedy about an obsessive teacher and an outcast student who bond over their shared misanthropy; a critic called it "one of those rare films from an up-and-coming auteur that shows both guts and playfulness.

[6] Lee has also appeared in minor roles in films directed by Ryoo Seung-wan, such as Timeless (2009), The Unjust (2010), and The Berlin File (2013).

In 2018, Lee married Pierce Conran, an Irish-Swiss film journalist and producer who has been based in Seoul since 2012.