HOCl has been implicated in the destruction of stratospheric ozone via a reaction catalyzed on ice surfaces in polar stratospheric clouds. Adsorption of HOCl on ice is a prototype of a simple ice surface reaction, and it has been the subject of several laboratory studies, making this a valuable case for testing theoretical approaches to ice surface reactions, The present paper describes a first-principles theoretical study of HOCl adsorption on ice, applying density functional theory (DFT) to cluster models of the (0001) surface of ice Jh. in The most stable binding configurations, HOCl acts as a proton donor in a hydrogen band. The strength of HOCl binding on the surface depends not only on the hydrogen bonding interaction but also on electrostatic and many-body interactions with neighboring water molecules. The results of these DFT calculations are compared to post-Hartree-Fock calculations of the H2O-HOCl complex and to empirical potential simulations of HOCl on ice.