Main cast
1. Lee Jung-jae as Seong Gi-hun
Seong Gi-hun is a driver and a gambling addict who lives with his mother and strives to support his daughter financially. He plays the game to pay off his numerous debts. Seong Gi-hun is player number 456.
2. Park Hae-soo as Cho Sang-woo
Cho Sang-woo is junior to Gi-hun and he is the leader of the investment team at a securities firm. Cho Sang-woo was a great student at Seoul National University. but he is now wanted by the police for stealing money from his clients. He is player number 218.
3. Jung Ho-yeon as Kang Sae-byeok
Kang Sae-byeok is a defector from North Korea who enters the Game in order to pay a broker to locate and recover her remaining family members who remain beyond the border. Kang Sae-byeok is player number 067.
4. O Yeong-su as Oh Il-nam (001)
Oh Il-nam, an old man suffering from a brain tumour who would rather play the Game than wait for death. Oh Il-nam is player number 001.
5. Heo Sung-tae as Jang Deok-su
Jang Deok-su is a gangster who enters the Game to settle his massive gambling debts. Jang Deok-su is player number 101.
6. Anupam Tripathi as Abdul Ali
As a result of Ali’s employer’s refusal to pay him for several months, Abdul Ali, a Pakistani immigrant, joins the game to help support his young family. Abdul Ali is player number 199.
7. Kim Joo-ryoung as Han Mi-nyeo
Han Mi-nyeo is a fascinating and cunning woman who poses as a destitute single mother. Han Mi-nyeo is player number 212.
8. Wi Ha-joon as Hwang Jun-ho
Hwang Jun-ho a police officer who enters the game as a guard in order to discover his missing brother.
Supporting cast
9. Yoo Sung-joo as Byeong-gi
Byeong-gi is a doctor who secretly collaborates with a group of corrupt guards to market the organs of deceased participants in exchange for information on future tournaments. Byeong-gi is player number 111.
10. Lee Yoo-mi as Ji-yeong
Ji-Yeong is a young woman who was recently freed from prison for murdering her abusive father. Ji-Yeong is player number 017.
11. Kim Si-hyun as Player
Player a clergyman who, while playing the game, rediscovers his faith. i-Yeong is player number 244.
12. Kim Yun-tae as Player 069
a player who joins the Game with his wife, Player 070.
13. Lee Ji-ha as Player 070
a player who joins the Game with her husband, Player 069.
14. Kwak Ja-hyoung as Player 278
A member of Deok-squad su’s who operates as his henchman.
15. Chris Chan as Player 276
A participant in the Tug of War round who joins Seong Gi-hun’s team.
Others
16. Kim Young-ok as Gi-hun’s mother
17. Cho Ah-in as Seong Ga-yeong, Gi-hun’s daughter
18. Kang Mal-geum as Gi-hun’s ex-wife and Ga-yeong’s mother
19. Park Hye-jin as Sang-woo’s mother
20. Park Si-wan as Kang Cheol / Sae-byeok’s brother
Special/Guest appearances
21. Gong Yoo as a salesman
A salesman who recruits participants for the Game.
22. Lee Byung-hun as The Front Man
The Front Man is the operator of the game who always wears a black diamond cut musk.
23. Lee Jung-jun as Guard
The Guard who unveil his face to the players on episode 3, and dies for this.