Purpose – A multitude of transparency movements have been developed and grown strong in recentdecades. Despite their growing influence, scholarly studies have focused on individual movements.The purpose of this paper is to make a pioneering contribution in defining transparency movements.Design/methodology/approach – An exploratory approach has been used utilizing movement-specificprofessional and scholarly documents concerning 18 transparency movements.Findings – Different traditions, ideologies of openness and aspects involving connections betweenmovements have been identified as well as forms of organization.Originality/value – This is the first attempt at identifying and defining transparency movements as acontemporary phenomenon.