Yass may refer to: People Catherine Yass (born 1963), painter Yazz, a British pop singer from the 1980s and 1990s Jeff Yass (born 1956), options trader, managing director and one of the five founders of the Philadelphia-based Susquehanna International Yoo "Yass" Sang-hoon, professional Rainbow Six Siege player for DWG KIA Places Yass, New South Wales, a town in Australia Municipality of Yass, original local government for the town until 1980 Yass Valley Council, a local government area (shire) in New South Wales since 2004 Yass Valley Way, the main road through Yass that was part of the Hume Highway before a bypass was constructed in the 1990s Yass River, a river in the state of New South Wales, Australia Other uses Yass (software), a genomic local alignment tool Yass (music), a style of Polish jazz music from the 1980s and 1990s Jass, a card game Yas (slang), a form of the word "yes" in LGBT slang