Il Cho Director, Screenwriter Yoo Ah-in Oh Joon-woo Actor Park Shin-hye Kim Yoo-bin Actor Jeon Bae-soo Mask man Actor Lee Hyun-wook Lee Sang-chul Actor Jin So-yeon Elena Kim Actor Oh Hye-won police officer Actor Lee Chae-kyung mask man's wife Actor Jeon Woon-jong firefighter infectee Actor Lee Gyoo-ho big infectee Actor Son Kyung-won security guard infectee Actor Shin Yeon-woo infected person 7 Actor Kim Hak-seon Oh Joon-woo's father Actor So Hee-jung Oh Joon-woo's mother Actor Joo Bo-Bi Oh Joon-woo's older sister Actor Jang Ji-gun ramen commercial model Actor Yoo Yeon sweater middle-age woman Actor Lee Dong-Kyu news reporter , debater Actor Matt Naylor Screenwriter Lee Eugene Producer Oh Hyojin Producer Son Won-ho Cinematographer Kim Seung-gyu Lighting Shin Min-kyung Film Editor Kim Tae-seong Music Seo Seong-gyeong Art Director