As a model in the 1990s, Byun walked the runways in Seoul, Paris and New York, notably for the brand Kenzo. She began acting in 2002, and starred in television dramas such as Women Next Door (2003), You"re Not Alone (2004), Can Love Be Refilled? (2005), The Last Scandal of My Life (2008) and Manny (2011). In 2005, Byun became the creative director for clothing label Ellahoya, when it launched its higher-end line for the Hyundai Home Shopping Network.
Known for her chic sense of style, in 2008 she became the host of talk show Olive Show, which featured trends in fashion.
Byun also created the make-up line Licht in 2009, and has written three books