Nam Joo-hyuk (Korean: 남주혁; born February 22, 1994) is a South Korean model and actor. He began his career as a model and appeared in several music videos before making his screen debut in 2014 with the television series The Idle Mermaid. He gained wide recognition with his role in the dramas Who Are You: School 2015 (2015) and Weightlifting Fairy Kim Bok-joo (2016). In 2018, he had his film debut with The Great Battle, and achieved further prominence with dramas Start Up (2020) and Twenty-Five Twenty-One (2022). In 2021, Nam was included in Forbes 30 Under 30.

Nam Joo-hyuk was born on February 22, 1994, in Yeongdo District, Busan, South Korea. During his studies in Gyeongnam Middle School [ko], Nam dreamed of becoming a professional basketball player, hence he played on the basketball team for three years, however after sustaining an injury and later undergoing an operation, he was forced to quit basketball. After moving to Seoul, he won the contest Top Model which was sponsored by K-Plus. Soon after, Nam signed an exclusive contract under the modeling agency.

Nam debuted in 2013 as a model for the SONGZIO Homme 2014 S/S collection. In 2014, he appeared in the music videos 200% and Give Love of fellow YG Entertainment artist Akdong Musician. Soon after, he made his acting debut as a supporting role in the tvN drama, The Idle Mermaid.

Nam landed his first major role in KBS's coming-of-age teen drama Who Are You: School 2015, in which he portrayed a high school student named Han Yi-an, who experiences growing pains such as a crush on a schoolmate and injuries affecting his swimming career. He garnered attention with his appearance in the series, eventually winning several accolades including Best New Actor at the 4th APAN Star Awards and the Popularity Award at the 2015 KBS Drama Awards.

In 2016, he played supporting roles in college romance series Cheese in the Trap and historical drama Moon Lovers: Scarlet Heart Ryeo. The same year, Nam became a cast member in the variety show Three Meals a Day. He then starred in his second lead role in the youth sports drama Weightlifting Fairy Kim Bok-joo alongside Lee Sung-kyung, portraying a talented yet playful swimmer named Jung Joon-hyung. Nam's performance in the series received favorable reviews and garnered him more widespread recognition.

In 2017, he led tvN's fantasy romance series The Bride of Habaek opposite Shin Se-kyung, wherein he portrayed a narcissistic Water God in pursuit of his rightful throne. Then in 2018, Nam starred in the historical film The Great Battle, which marked his big screen debut. Nam received acclaim for his performance, with Yoon Mi-sik of The Korea Herald writing that he "delivers a rock-solid portrayal of a wavering youth who is unsure of what is right or wrong." His performance in the film led him to win Best New Actor accolades at the prestigious Blue Dragon Awards.

Nam starred in the fantasy romance drama The Light In Your Eyes alongside Han Ji-min and Kim Hye-ja in 2019, receiving positive reviews for his performance. In 2020, Nam starred in Netflix's supernatural crime drama The School Nurse Files and in the tvN romance series Start-Up. The same year, Nam also starred in the romance film Josée, a remake of the 2003 Japanese film Josee, the Tiger and the Fish. The film reunites Nam with The Light In Your Eyes co-star Han Ji-min. With the success of The School Nurse Files and Start-Up, Nam was featured in Forbes' 30 Under 30 Asia list under the "Entertainment & Sports" category in 2021.

Nam then worked with Kim Tae-ri in leading the tvN drama Twenty-Five Twenty-One. The series, which tells the story of love between a man and a woman who met in the midst of the IMF crisis set in 1998, premiered in February 2022. He received favorable reviews for his performance in portraying the character Baek Yi-jin, with Korean media outlet OSEN referring to Nam as the "symbol of youth" as they commended his acting skills which created what is known as the "Joohyuk's Pain" syndrome. Writer Kim Bo-ra cited his "solid physique, warm-hearted visuals, and deep sensibility" which made him "look like a character in a teen comic." Kim adds, "[Nam's] affectionate warm voice and clear gaze make viewers' hearts flutter and fall for Baek Yi-jin."