The Organisation Intersex International (OII) is a global advocacy and support group for people with intersex traits. According to Milton Diamond, it is the world's largest organization of intersex persons. A decentralised network, OII was founded in 2003 by Curtis Hinkle. Upon Hinkle's retirement, American intersex activist Hida Viloria served as Chairperson/President elect from April 2011 through November 2017, when they resigned in order to focus on OII's American affiliate, OII-USA's transition into the independent American non-profit, the Intersex Campaign for Equality.