Halys

Halys may refer to:


 * Health-adjusted life years (HALYs), a type of disability-adjusted life year which are used in attempts to quantify the burden of disease or disability in populations
 * Halys River, a western name for the Kızılırmak River (Turkish: "Red River") in Anatolia
 * Halys (bug), a genus of stink bugs
 * A taxonomic synonym for the genus Gloydius, also known as Asian moccasin snakes, a group of venomous pitvipers found in Asia
 * Gloydius halys, also known by the names Halys viper and Halys pit viper
 * Quentin Halys (born 1996), French tennis player