Pro Bono

Main

• Jung Kyung-ho as Kang Da-wit^[2]
  • Park Yoon-ho as teen Da-wit^[3]
  • Choi Jae-yoon as young Da-wit

A former judge who becomes a public interest lawyer.

• So Joo-yeon as Park Gi-ppeum^[2]
  • Kim Tae-yeon as young Gi-ppeum

A law expert who earns admiration through in-depth knowledge.

Supporting

Guest appearances

• Shin Hye-ji [ko] as Baek Han-byeol, the granddaughter of Baek Joong-seop, who runs a dog café.^[7]
• Lee Moon-sik as Shin Jung-suk, Chief Justice (Ep. 1, 4, 9–12)^[8]
• Kim Jung-young as Kim Sung-rye, Kang Da-wit's mother whose hand was severed due to excessive overtime in Yoo Jae-bum's father's factory and then passed away suddenly when Da-wit was a high school student (Ep. 1, 2, 5, 9)^[9]
• Yun Je-wook as Yoo Jae-bum, a conman who pretended to be Kang Da-wit's elementary school classmate in order to take revenge against Da-wit by framing him for receiving a bribe (Ep. 1, 8–10)^[9]
• Lee Kang-wook as Kim Do-hoon / Goo Ji-hwan, a journalist who is friends with Kang Da-wit and a lawyer who earns money by taking on cases through illegal means (Ep. 1, 2, 4, 6–9)^[10]
• Sung Dong-il as Choi Ho-jip, Chief Judge who is notorious for his prickly nature in the legal community (Ep. 2)^[11]
• Yoon Sang-jung as Ji So-yun, the rescuer of the puppy Byuli (Ep. 2)^[12]
• Lee Chun-moo as Kim Kang-hoon, a 12-year-old child on wheelchair due to paraplegia and wants to sue God for damages (Ep. 3, 4)^[13]
• Jung Sae-byul as Jung So-min, Kang-hoon's mother who is pushed to the limits of life while raising her disabled son alone (Ep. 3, 4)^[14]
• Yoo Jae-myung as Choi Woong-san, Woongsan Group and hospital's chairman who advocates anti-abortion hospital policy due to his religious beliefs (Ep. 4)^[15]
• Choi Hee-jin as Kim Jin-oh, a visually impaired judge (Ep. 3)^[16]
• Lee Dae-yun as Kook Young-joon, the appellate court judge (Ep. 3, 4)^[17]
• Jung Hoe-ryn as Kaya, an immigrant from Myanmar who wants a divorce due to her father-in-law's sexual assault (Ep. 5, 6)^[18]
• Sung Yu-jin as Goo Ji-won, the judge who grants Kaya's divorce case and allows her to maintain her residency status (Ep. 5, 6)^[19]
• Lee Jong-won as Jo Kang-ryul, Chief Judge who believes in South Korea being a country of freedom and justice (Ep. 6)^[20]
• Jung Ji-so as Elijah, popular singer/idol who has been continuously harassed by cyber-bullying activist Ma Young-sook and by some fans obsessed with her (Ep. 7, 8)^[21]
• Oh Min-ae as Cha Jin-hee, Elijah's domineering and manipulative mother who is the CEO of her agency 'EK Entertainment' (Ep. 7, 8)^[22]
• Jang Duk-soo as Kang Min-ha, employee at a luxury brand store taking the stand as a key witness against Cha Jin-hee (Ep. 8)^[23]
• Kim Yong-joon as Yoon Baek-man, Yoo Jae-bum's father who owned a paper factory where Kang Da-wit's mother worked (Ep. 9, 10)^[24]
• Song Young-chang as Jang Hyun-bae, a powerful conglomerate chairman who was sentenced to a heavy prison term by Kang Da-wit for habitual assaults on employees and a forced sexual assault on a domestic helper (Ep. 1, 11–12)^[25]

Development

Pro Bono is written by Moon Yoo-seok, directed by Kim Seong-yoon, planned by Studio Dragon, and co-produced by Sequence One, Lotte Cultureworks, and Studio Flow.^[2]

Casting

On February 19, 2025, it was reported that Jung Kyung-ho would star in the series.^[26] On March 26, Lee Yoo-young was reported to be cast as the lead.^[27] Jung Kyung-ho and So Joo-yeon were officially confirmed to star on April 28.^[28] On April 30, Choi Dae-hoon was set to make a special appearance.^[29] On October 30, Yoon Na-moo, Seo Hye-won, and Kang Hyung-seok were officially revealed to have joined the cast as part of the pro bono team alongside Jung and So.^[2][30]

Music

The OST singer lineup, which includes K.Will, Gyeong-gye, John Park, Namjong, and Yangpa, was unveiled by Curiosity Studio on December 1, 2025. The music director of the series is Park Sung-il.^[31]