BYS may refer to:
* "B.Y.S.", a song from the album ''
Daily Operation'' by Gang Starr
*
Baggio–Yoshinari Syndrome
The Baggio–Yoshinari syndrome , formerly known as the Brazilian Lyme-like disease and Brazilian human borreliosis, is a disease transmitted by the '' Amblyomma cajennense'' tick, but the organism that causes the infection is still unknown. Clini ...
, a tick-borne disease found in Brazil
*
Boston Youth Symphony
{{disambiguation