Secret Door is a 2014 South Korean television series starring Han Suk-kyu, Lee Je-hoon, Kim Yoo-jung, Park Eun-bin, Kim Min-jong, and Choi Won-young. It aired on SBS on Mondays and Tuesdays at 22:00 from 22 September to 9 December 2014 for 24 episodes.

Han Suk-kyu is a South Korean actor. One of the leading actors of Korean cinema, Han's notable works include Green Fish (1997), No. 3 (1997), Christmas in August (1998), Shiri (1999), The Scarlet Letter (2004), and The President's Last Bang (2005), and Dr. Romantic (2016–2023).