Mowg (Korean: 모그; RR: Mogeu), born as Lee Sung-hyun (Korean: 이성현, born in 1972), is a musician and composer of film scores. He adopted the name Mowg after his peers in New York nicknamed him due to his resemblance to Mowgli from The Jungle Book when he was in his 20s.

Mowg is recognized for his frequent collaborations with director Kim Jee-woon, beginning with their first project, the omnibus film Doomsday Book (started in 2006, released in 2012). They have since worked together on several other works, including I Saw the Devil (2010), The Last Stand (2013), One Perfect Day (short film, 2013), The X (short film, 2013), The Age of Shadows (2016), Illang: The Wolf Brigade (2018), Untact (short film, 2020), Dr. Brain (Apple Original Series, 2021), and Cobweb (2023).

Mowg has received multiple awards for his contributions to various films, such as I Saw the Devil (2010), Masquerade (2012), Hwayi: A Monster Boy (2013), Dongju: The Portrait of a Poet (2016), The Age of Shadows (2016) and Burning (2018).

In addition to his film work, Mowg produced albums by other artists, including the debut album by Korean star Jang Yoon-ju titled Dream, and Jazz album of vocalist Malo.