Yoo Na-ul (Korean: 유나얼; born September 23, 1978),[1] better known by the mononym Naul (Hangul: 나얼), is a South Korean singer, artist, and member of Brown Eyed Soul, signed under in Next Music.

[2][3][4][5] He released his debut solo album, Back to the Soul Flight, on January 8, 2005.

The group participated in SBS's New Era Music Competition in 1998, at which point they won the grand prize with the song "Letting You Go".

[8][non-primary source needed] In 2001 Naul paired with Yoon Gun for the duo Brown Eyes.

[11] Naul has released several solo albums, the second of which was predominantly composed of song covers.