Lee Dong-seok (; born March 1, 1971), better known by the stage names Ma Dong-seok () and Don Lee, is an American actor and film producer based in South Korea. He gained early recognition for his supporting roles in ' (2012) and The Neighbor (2012).
Ma rose to prominence with his breakout performance in Train to Busan (2016), where he played a tough yet compassionate survivor, earning widespread acclaim. He cemented his status as a leading action star with The Outlaws (2017), in which he portrayed the relentless detective Ma Seok-do, a role he reprised in the highly successful The Roundup film series. His subsequent leading roles include ' (2018), The Gangster, the Cop, the Devil (2019), ' (2019), Start-Up (2019), and Ashfall (2019).
In 2021, Ma made his Hollywood debut in the Marvel Cinematic Universe film Eternals, which further expanded his global recognition. He remains one of South Korea's most bankable stars and was named Gallup Korea's Film Actor of the Year in 2018, 2023, and 2024.
Ma was born in South Korea. He had South Korean citizenship until 1989 (when he was aged 18), after which he forfeited his South Korean citizenship and became an American citizen. He returned to South Korea at age 30 and began acting.
Ma rose to fame for his supporting roles in the films The Neighbor, ', and The Unjust. He then played leading roles in Norigae, Murderer, and One on One.
Ma's role in the zombie film Train to Busan propelled him to international popularity. His subsequent leading roles in films Derailed, The Bros, The Outlaws, Unstoppable, Champion, The Gangster, the Cop, the Devil, ' and The Roundup along with supporting roles in ' and Ashfall have met with critical and commercial successes led him to Most Bankable Star of Korean Cinema. Although known for his 'tough guy' persona roles, Ma is often celebrated and criticized for playing similar roles in his movies. In 2019, he joined the cast of the MCU film Eternals as Gilgamesh which marked his Hollywood debut. On television, Ma is known for his roles in the hit OCN series Bad Guys and Squad 38.
In 2022, Ma signed a contract with LDH Japan, another large Japanese agency. His 2022 release action crime thriller The Roundup, sequel to his 2017 film The Outlaws not only opened to unanimous positive reviews but also became the highest-grossing film of 2022 by surpassing 12 million admissions for the first time since 2019 and all time 3rd highest grosser in South Korea. In 2024, dystopian film Badland Hunters in which Ma is playing role of wasteland hunter was released on January 26 on Netflix.
In 2026 he is set to star in an action-adventure videogame developed by Nagoshi Studio, founded by Toshihiro Nagoshi entitled Gang of Dragon.
Under his Westernized name, Don Lee, and before he turned to acting, Ma was the personal trainer of mixed martial artists Mark Coleman and Kevin Randleman.
With his production company Team Gorilla, Ma is currently involved in planning and writing screenplays. He worked on the screenplay for the film Deep Trap, in which he starred. He is also the co-creator of the OCN Dramatic Cinema series '.
Ma has been an amateur armwrestler since 2008, and he became the president of Korea Armwrestling Federation in 2018.
In 2016, Ma was reportedly dating sports reporter and media personality . On October 20, 2022, Ma's agency stated that he and Ye had registered their marriage the previous year. The wedding ceremony would be held at a later date, due to the COVID-19 pandemic and busy schedules.