Lee Mu-jin (; born December 28, 2000) is a South Korean singer and songwriter. He rose to fame after appearing on the music audition show Sing Again in 2020, in which he finished in 3rd place. His 2021 single, "Traffic Light", spent three weeks at number one on South Korea's Gaon Digital Chart. Since 2022, he is the main host on KBS music web show, LeeMujin Service.
Lee was born in Goyang, Gyeonggi Province, South Korea. He is a student at Seoul Institute of the Arts.