South Africa’s constitutional revolution has profoundly affected its administrative law. Since 1994 South Africans have enjoyed constitutional rights to administrative justice as well as a range of other constitutional safeguards. More recently legislation mandated by the 1996 Constitution has been enacted, in the form of the Promotion of Administrative Justice Act 3 of 2000, to give effect to the constitutional administrative-justice rights. This thesis describes and critically assesses the transformation of South African administrative law since 1994 with particular reference to that legislation. The essential transformative promise of the democratic Constitution is to replace the old, pre-democratic culture of authority with a culture of justification. Drawing on the seminal Breakwater Declaration of 1993, the most serious deficiencies of the pre-democratic law are indentified as consisting in narrow and impoverished grounds of review; restricted access to judicial remedies; an overly formalistic style of judicial reasoning; and an incomplete system of administrative law, the result of a paucity of safeguards apart from judicial review. Conversely, the main aspirations of a transformed administrative law – the law associated with a culture of justification – are identified as well-developed grounds of review; improved access to judicial remedies; the achievement of a more substantive style of judicial reasoning; and the completion of administrative law through the supplementation of judicial review. The transformation of the law in relation to each of these four aspirations is investigated in turn. It is concluded that South African administrative law the transformative promise of the democratic Constitution has been realised to a great extent.