Lee was born on December 15, 1972, in Jung District, Seoul. He attended Dongguk University, earning a master’s degree from the Department of Theater & Film Art in 2008. That same year, he made his theater debut in "Hamlet in Water," performed at his alma mater’s Lee Hae-rang Theater.

Recognized as one of South Korea's top actors, he has won numerous awards, including a Primetime Emmy Award, a Screen Actors Guild Award, a Critics' Choice Television Award, and six Baeksang Arts Awards.

He has also been nominated for a Golden Globe and a Gotham Award. Besides acting, Lee is a successful businessman with a chain of restaurants in Seoul and several businesses, including the development company Seorim C&D, which he co-owns with fellow actor and close friend Jung Woo-sung.

Lee was born in Seoul and started his career as a fashion model before transitioning to television with his debut in the drama "Sandglass" (1995). He gained widespread recognition with the film "An Affair" (1998), which propelled his film career.

Lee has since starred in various genres, including dramas like "City of the Rising Sun" (1999), romantic films like "Il Mare" (2000) and "Last Present" (2001), comedies like "Oh! Brothers" (2003), action films like "Typhoon" (2005) and "Deliver Us from Evil" (2020), and thrillers like "The Housemaid" (2010) and "New World" (2013). He also won Best Supporting Actor at the 50th Baeksang Arts Awards for his role in "The Face Reader" (2013).

In 2021, Lee gained international fame for his role as Seong Gi-hun in Netflix's survival drama "Squid Game." His performance earned him numerous accolades, making him the first male actor from Asia and Korea to receive nominations across four major award shows: Critics' Choice Television Award, Golden Globe, Primetime Emmy, and Screen Actors Guild Award.
He won the latter two, making history in the process.

Lee was also named Gallup Korea's Film Actor of the Year in December 2021 and listed among the most impactful Asians on the A100 list by Gold House in 2024. He is set to reprise his role in "Squid Game’s" second season, which began filming in July 2023.

Lee was discovered by designer Ha Yong-soo while working at a café in Apgujeong-dong, Gangnam District, and then worked as a fashion model. He made his acting debut in the 1993 TV drama "Dinosaur Teacher," quickly becoming a star and securing lead roles.

His role in the 1994 campus drama "Feelings" made him a household name. In 1995, his supporting role in "Sandglass" turned him into a national heartthrob, leading to increased screen time. However, his career paused for mandatory military service.

After returning from the military in 1997, Lee's career initially declined. He then enrolled in acting school at Dongguk University's Department of Drama and Film.

His breakthrough came with the film "An Affair" (1998), followed by "City of the Rising Sun" (1999), for which he won Best Actor at the Blue Dragon Film Awards. Despite "Il Mare" (2000) not being a hit, it gained a loyal fan base. Lee's subsequent films, "Last Present" and "The Last Witness," were successful. In 2003, he starred in the comedy "Oh! Brothers," one of his biggest hits, followed by the action film "Typhoon" (2005).

Lee's return to television with "Air City" (2007) and "Triple" (2009) did not succeed in ratings. He then took on a different kind of role in the action comedy "The Accidental Gangster and the Mistaken Courtesan" (2008), which, despite its box office failure, remained a memorable film for him.

Lee's career revived with the 2010 erotic thriller "The Housemaid," showcased at Cannes and Toronto. He starred in the box office hit "The Thieves" (2012) and the art film "El Fin del Mundo" (2012). His role in "New World" (2013) earned him a Best Supporting Actor award for "The Face Reader" (2013). Other notable films include "Big Match" (2014), "Assassination" (2015), "Operation Chromite" (2016), and "Along with the Gods: The Two Worlds" (2017).

In 2019, Lee starred in "Svaha: The Sixth Finger" and returned to TV with "Chief of Staff." His role in "Squid Game" (2021) brought him international fame, earning historic nominations and awards. He became a global ambassador for Gucci and will reprise his role in "Squid Game" Season 2.

In 2022, Lee directed "Hunt," premiering at Cannes. He signed with Creative Artists Agency and joined the "Star Wars" series "The Acolyte." He also received South Korea's highest cultural honor, the Geumgwan Order of Cultural Merit.

Apart from acting, Lee is known for launching a chain of upscale Italian restaurants in Seoul named after his film Il Mare. Having studied interior design, he was responsible for designing the interiors of his restaurants.

In 2008, Lee founded the real estate development company Seorim C&D. He also co-owns several businesses with actor Jung Woo-sung, a close friend he first worked with on the film City of the Rising Sun. In May 2016, Lee and Jung established their entertainment label, Artist Company, where they both serve as CEOs.

On March 8, 2022, Lee donated ₩100 million to the Hope Bridge Disaster Relief Association along with Jung Woo-sung to help the victims of the massive wildfire that started in Uljin, Gyeongbuk, and spread to Samcheok, Gangwon. On August 3, 2022, the Hope Bridge Disaster Relief Association announced that Lee and Jung joined the Hope Bridge Honors Club, a group of major donors with contributions exceeding ₩100 million.

In 1999, Lee was charged with driving under the influence (DUI) after crashing his BMW into a car in an adjacent lane. His blood alcohol content was 0.222%, leading to the revocation of his driver's license. He faced another DUI in 2002, resulting in another license revocation.

In January 2015, it was officially confirmed that prominent South Korean actor Lee Jung-jae was in a romantic relationship with Lim Se-ryung.

Lim Se-ryung is notable for being the former wife of Lee Jae-yong, the vice chairman of Samsung Electronics and the heir apparent to the Samsung conglomerate. This relationship garnered significant media attention due to the high-profile status of both individuals.

Prior to his relationship with Lim Se-ryung, Lee Jung-jae had been romantically linked with actress Kim Min-hee. The couple's previous relationship had also been a topic of public interest, given Kim Min-hee's recognition in the South Korean entertainment industry.