Undercover

Director

• 
  Song Hyun Wook
• 
  Park So Yeon

Screenwriter

• 
  Jung Hye Eun
• 
  Song Ja Hun
• 
  Baek Chul Hyun

Main Role

• 
  Ji Jin Hee

  Han Jeong Hyeon [Present]

  Main Role
• 
  Kim Hyun Joo

  Choi Yeon Su [Present]

  Main Role
• 
  Huh Joon Ho

  Im Hyeong Rak

  Main Role
• 
  Jung Man Sik

  Do Yeong Geol

  Main Role

Support Role

• 
  Yoo Seon Ho

  Han Seung Gu [Jeong Hyeon & Yeon Su's son]

  Support Role
• 
  Lee Jae In

  Han Seung Mi [Jeong Hyeon & Yeon Su's daughter]

  Support Role
• 
  Lee Han Wi

  Bae Gu Taek

  Support Role
• 
  Han Go Eun

  Ko Yun Ju

  Support Role
• 
  Kwon Hae Hyo

  O Pil Jae

  Support Role
• 
  Kang Young Seok

  Jung Cheol Hun [Detective]

  Support Role
• 
  Bae Yoon Kyung

  Song Mi Seon

  Support Role
• 
  Choi Dae Chul

  Chu Dong U

  Support Role
• 
  Lee Seung Jun

  Kang Chung Mo

  Support Role
• 
  Son Jong Hak

  Yoo Sang Dong

  Support Role
• 
  Kim Soo Jin

  Min Sang A

  Support Role
• 
  Choi Kwang Il

  Hwang Jeong Ho

  Support Role
• 
  Joo Seok Tae

  Park Won Jong

  Support Role
• 
  Park Jin U

  Detective Koo

  Support Role
• 
  Song Young Gyu

  Kwak Mun Heum [Chief prosecutor]

  Support Role
• 
  Kim Dong Ho

  Woo Jin [Hyeong Rak's subordinate]

  Support Role
• 
  Cha Soon Bae

  Song Moon Bae

  Support Role
• 
  Park Doo Shik

  Do Yeong Geol [Young]

  Support Role
• 
  Seo Joon

  Hyeon Pil

  Support Role
• 
  Ahn Se Ho

  Kim Gwang Cheol

  Support Role

Guest Role

• 
  Im Ji Gyu

  Hwang Jeong Ho [Young] (Ep. 1)

  Guest Role
• 
  Jang Eui Don

  [Police university instructor] (Ep. 1)

  Guest Role
• 
  Kim Kye Hyung

  [Car passenger] (Ep. 1)

  Guest Role
• 
  Choi Hong Lag

  (Ep. 1)

  Guest Role
• 
  Nam Sung Jin

  Cha Min Ho (Ep. 1-2)

  Guest Role
• 
  Hong Jin Ki

  Kang Chung Mo [Young] (Ep. 1-2, 8)

  Guest Role
• 
  Moon Joo Won

  Han Seung Gu [Young] (Ep. 2)

  Guest Role
• 
  Richard Kim

  Park Ju Won [NIS hearing attendee] (Ep. 2)

  Guest Role
• 
  Kim Byung Soon

  Yang Ho Won [Assemblyman] (Ep. 2)

  Guest Role
• 
  Yoo Byung Sun

  [Scrapyard crane operator] (Ep. 2)

  Guest Role
• 
  Kim Young Dae

  Kim Tae Yeol (Ep. 2-3, 8)

  Guest Role
• 
  Kong Joon Min

  Attorney Park (Ep. 2, 15)

  Guest Role
• 
  Kim Young Woong

  [Subway control room staff] (Ep. 3)

  Guest Role
• 
  Kim Gyeong Min

  Mr. Park (Ep. 3-4)

  Guest Role
• 
  Shim Hyung Tak

  Lee Min Yul (Ep. 3-4)

  Guest Role
• 
  Kim Hye Jin

  Jeong Hui [Min Ho's wife] (Ep. 3-4)

  Guest Role
• 
  Jung In Ki

  Kim Myeong Jae [Secretary general] (Ep. 3-4)

  Guest Role
• 
  Hong Ye Ji

  [Reporter] (Ep. 3-4)

  Guest Role
• 
  Lee Se Na

  Kim Da Gyeong (Ep. 4)

  Guest Role
• 
  Park Kyung Ri

  Ko Yun Ju [Young] (Ep. 4)

  Guest Role
• 
  Nam Hee Soo

  [ID office clerk] (Ep. 4)

  Guest Role
• 
  Park Joo Hyung

  [Drug gang boss] (Ep. 4, 11)

  Guest Role
• 
  Kim Do Vin

  (Ep. 4, 13)

  Guest Role
• 
  Kim Jong Ho

  [Attorney] (Ep. 5)

  Guest Role
• 
  Jung Dong Gyu

  Lee Gang Ho (Ep. 5-6)

  Guest Role
• 
  Park Jung Eon

  Lee Yeong Suk (Ep. 5-6)

  Guest Role
• 
  Seo Young Sam

  Park Yeong Su (Ep. 5-6)

  Guest Role
• 
  Lee Yoon Sang

  Park Ju Won (Ep. 5-6)

  Guest Role
• 
  Kim Jung Jin

  Kim A Sun (Ep. 5-6)

  Guest Role
• 
  Choi Gyo Shik

  Priest Ha (Ep. 5-6)

  Guest Role
• 
  Kim Jin Goo

  Kim Dong Yeong (Ep. 6)

  Guest Role
• 
  Lee Eun Ju

  Hwang Hyeon Ju (Ep. 6)

  Guest Role
• 
  Han Seung Yup

  Han Sang Jin (Ep. 6)

  Guest Role
• 
  Do Mi Yeon

  Ko Yu Ri (Ep. 6)

  Guest Role
• 
  Kim Deok Ju

  [A Sun's mother] (Ep. 6)

  Guest Role
• 
  Jun Joon Woo

  [Police officer] (Ep. 6)

  Guest Role
• 
  Shin Bi

  Jang Yu Bin (Ep. 6, 8-9)

  Guest Role
• 
  Kim Do Won

  [Hyeong Rak's grandson] (Ep. 7)

  Guest Role
• 
  Yeon Je Wook

  [Loan shark] (Ep. 7)

  Guest Role
• 
  Park Woo Jae

  [CIO security guard] (Ep. 7)

  Guest Role
• 
  Kim Nam Jin

  [Myeong Jae's wife] (Ep. 7-8)

  Guest Role
• 
  Jeon Hye Won

  [Myeong Jae's daughter] (Ep. 7-8)

  Guest Role
• 
  Seong Byung Sook

  [Tae Yeol's mother] (Ep. 8)

  Guest Role
• 
  Lee Moo Nyoung

  [CIO protester] (Ep. 8)

  Guest Role
• 
  Jin Shi Won

  [Reporter] (Ep. 8)

  Guest Role
• 
  Han Jae Young

  [Yeoyeong Inn owner] (Ep. 8-9)

  Guest Role
• 
  Oh Ki Hwan

  Kon Sun Chun [Prosecutor] (Ep. 8-9)

  Guest Role
• 
  Kim Dong Gon

  [News program panelist] (Ep. 8)

  Guest Role
• 
  Gi Hwan

  Ryu Seong Hyeon [Prosecutor] (Ep. 8-9)

  Guest Role
• 
  Lee Jin Seung

  Park Jun Suk (Ep. 8-9)

  Guest Role
• 
  Gyeol Hwi

  Park Du Sik [Young] (Ep. 8, 11)

  Guest Role
• 
  Kim Sung Yong

  Jeon Hong Go (Ep. 9)

  Guest Role
• 
  Nam Jung Woo

  Won Bok Dong [Sergeant] (Ep. 9)

  Guest Role
• 
  Kwon Tae Won

  [Police officer] (Ep. 9-10)

  Guest Role
• 
  Yoo Mi Sun

  [Saleswoman] (Ep. 10)

  Guest Role
• 
  Han Bo Bae

  Min Sang A [Young] (Ep. 10, 16)

  Guest Role
• 
  Kim Joo Ah

  [Orphanage employee] (Ep. 11)

  Guest Role
• 
  Park Sang Yong

  [Won Jong's attorney] (Ep. 12)

  Guest Role
• 
  Kim In Suk

  [Real estate agent] (Ep. 7)

  Guest Role
• 
  Lee So Ra

  [Nurse] (Ep. 10)

  Guest Role
• 
  Jang Myoung Un

  [Hyeong Rak's security team] (Ep. 14)

  Guest Role
• 
  Min Choong Suk

  [Police officer] (Ep. 15)

  Guest Role
• 
  Yook Mi Ra

  [Assemblywoman] (Ep. 15)

  Guest Role
• 
  Park Jae Wan

  Assemblyman Cho (Ep. 15)

  Guest Role
• 
  Lee Jae Woo

  [Assemblyman] (Ep. 15)

  Guest Role
• 
  Jeong Seung Wook

  [Reporter] (Ep. 15)

  Guest Role
• 
  Ma Jung Pil

  Attorney Park (Ep. 16)

  Guest Role
• 
  Kwon Ji Hwan

  [Agent] (Ep. 16)

  Guest Role
• 
  Kim Dong Ho

  Cheon U Jin

  Guest Role
• 
  Im Jung Ok

  Nurse KIm

  Guest Role
• 
  Yoon Tae Soo

  [Student protestor]

  Guest Role
• 
  Lee Hwi Won

  [Senior gangster]

  Guest Role
• 
  Lee Dong Soo

  [Interviewer]

  Guest Role
• 
  Jeon Se Yong

  [Public hearing host]

  Guest Role
• 
  Lee Ha Eum

  [Hankuk University student protestor]

  Guest Role
• 
  Yoo In Sun

  [Airborne Division employee]

  Guest Role
• 
  Son Jeong Won

  [CIO staff]

  Guest Role
• 
  Min Tae Hong

  [Freshman protester]

  Guest Role
• 
  Kim Jin Kyu

  [Daehan Jeil Daily staff]

  Guest Role
• 
  Park Jong Wook Guest Role
• 
  Joo In Ae Guest Role

Cameo

• 
  Park Geun Hyung

  Lee Man Ho (Ep. 1-2)

  Cameo
• 
  Han Sun Hwa

  Choi Yeon Su [Young] (Ep. 1-3, 8, 10, 12, 14-16)

  Cameo
• 
  Yeon Woo Jin

  Han Jeong Hyeon / Lee Seok Gyu [Young] (Ep. 1-5, 7-10, 12, 14-16 )

  Cameo
• 
  Myung Gye Nam

  [Judge] (Ep. 16)

  Cameo

Unknown

• 
  Kim Young Hee Unknown
• 
  Park Tae Jin Unknown