Lee Jong-suk (Korean: 이종석, born September 14, 1989) is a South Korean actor and model. He debuted in 2005 as a runway model and gained recognition as an actor with television series School 2013 (2012) and I Can Hear Your Voice (2013). He received further prominence with dramas Doctor Stranger (2014), Pinocchio (2014), W (2016), While You Were Sleeping (2017), and Big Mouth (2022).

Lee majored in Professional Motion Pictures and Art at Konkuk University and graduated from the university in 2016.

At 15, Lee began his modelling career at the Seoul Collection walkway in 2005, making him the youngest male model to debut in the Seoul Collection program at Seoul Fashion Week. Since then, he has walked in a number of fashion shows. Lee trained as an idol group member for three months, and had signed on with an agency to debut. However, he quit after the agency broke their promise of debuting him as an actor. He took part in a selection for actors at SBS TV station when he was in middle school. In 2010, Lee made his official acting debut in the South Korean TV series Prosecutor Princess. He also made his big-screen debut in the horror movie Ghost.

Lee started to gain recognition following his supporting role in the hit drama Secret Garden where he played a talented young composer with a surly attitude and a forbidden crush on the second male lead. In 2011, he appeared in MBC's sitcom High Kick Season 3 where he gained further popularity. Lee also co-starred in the film R2B: Return to Base in 2012, a loose remake of the critically acclaimed 1986 film Top Gun.

Lee's breakout role came as a high school student in the teen drama School 2013. He received his first acting award for the role at the 2012 KBS Drama Awards under the category Best New Actor. He also ranked fifth according to a survey entitled 'Actors Who Lit Up 2013' by Gallup Korea.

Following the success of School 2013, Lee starred in the critically acclaimed drama series I Can Hear Your Voice with Lee Bo-young. He played Park Soo-ha, an intelligent young man who can read minds. Originally slated for 16 episodes, the drama was extended by two episodes due to its successful ratings. He received the Excellence Award in the male category at the Korea Drama Awards for his performance. Lee then starred in the sports film No Breathing and had a supporting role in the box office hit The Face Reader.

In 2014, he starred in teen romantic comedy Hot Young Bloods, playing a cheesy womanizer. Lee then starred in hit medical drama Doctor Stranger, playing a North Korean defector who works as a doctor in South Korea. The drama was a success in China, gaining 400 million views. Lee next starred in Pinocchio opposite actress Park Shin-hye, and played the protagonist Choi Dal-po, a first year reporter at a broadcasting company who struggles with the idea of justice and truth in a world where everyone wants to hide the facts. Pinocchio was another hit, with a reported revenue of 6.2 billion won (US$5.62 million) for broadcasting rights in just one year. Lee's performances in the dramas Doctor Stranger and Pinocchio earned him acting accolades, including the Male Top Excellence Award at the 8th Korea Drama Awards. He also became the youngest actor to win the Best Actor award at the 27th Grimae Awards, chosen by television cinematographers.

Lee then embarked on an Asia fan-meeting tour, and released a photobook titled 2014–2015 Asia Tour Story ~With~, comprising photos taken of Lee's meetings with fans in seven Asian cities during the nine-month tour. Lee was also cast in his first Chinese drama entitled Jade Lovers alongside actress Zheng Shuang. The drama, filmed in Shanghai, is described as a fantasy romance series set in the 1930s. Due to Lee's success in China, a wax figure of him went on display in Hong Kong's Madame Tussauds, which the actor unveiled himself in a ceremony. In December 2015, Lee left his previous agency Wellmade Yedang and signed an exclusive contract with YG Entertainment on 10 May 2016.