HYS or HyS may refer to:
Hayes railway station (station code: HYS), a railway station located in Hayes in the London Borough of Bromley Hays Regional Airport (IATA code: HYS), a general-aviation airport in Ellis County, Kansas Heep Yunn School, an Anglican girls' secondary school in Hong Kong Hybrid sulfur cycle (HyS), a two-step water-splitting process HYS The Hague, the ice hockey club in The Hague, Netherlands