Ki Hong Lee was born in Seoul, South Korea. He grew up there, until the age of 6, when he and his family moved to Auckland, New Zealand, where he learned to speak in English. Two years later, when Lee was about 8, he and his family moved to Los Angeles. He lived in Southern California for most of his life, before attending UC Berkeley for his undergraduate degree from 2004 to 2008.

In 2010, Lee debuted his acting career with guest-appearance roles in the television series Victorious, The Secret Life of the American Teenager, and Modern Family.^[3] In 2011, he played the role of Paul on the ABC Family show The Nine Lives of Chloe King. Lee also appeared in a few short films by Wong Fu Productions, such as Ben in Away We Happened(2012), She Has A Boyfriend (2013) and This Is How We Never Met (2013). He rose to fame after being cast in the role of Minho in The Maze Runner (2014).