Sly was a Japanese heavy metal supergroup formed in 1994 by former members of popular groups of the Japanese metal scene.

The line-up included singer Minoru Niihara and drummer Munetaka Higuchi (both from Loudness), guitarist Shinichiro Ishihara (Earthshaker) and bassist Koichi Terasawa (Blizard).

[1] Sly disbanded in 1998,[1] with Niihara and Higuchi re-joining Loudness in 2000 and Ishihara taking part in the reformation of his former group Earthshaker in 1999.