This chapter considers the issue of segregation in Australian prisons. It examines relevant legislation, policy and practices in state and territory correctional systems and evaluates them by reference to international human rights standards, with particular reference to the UN Standard Minimum Rules for the Treatment of Prisoners. The chapter considers the provisions authorising segregation, the duration and conditions of segregation, and processes for accountability and review. Specific aspects of segregation discussed include indefinite confinement, administrative segregation, conditions in protection cells, prison lockdowns, and the contribution of segregation to self harm and Indigenous deaths in custody.