The Anarchical Society: A Study of Order in World Politics is a 1977 book by Hedley Bull and a founding text of the so called English School of international relations theory. The title refers to the assumption of anarchy in the international system (posited primarily by realists) and argues for the existence of an international society.

The book also outlines Bull's theory of new medievalism.

Hedley Bull, FBA (born Sydney, Australia, 10 June 1932 – died, Oxford, England, 18 May 1985) was Professor of International Relations at the Australian National University, the London School of Economics and the University of Oxford until his death from cancer in 1985. He was Montague Burton Professor of International Relations at Oxford from 1977 to 1985.

n 1977, Bull published his main work, The Anarchical Society. It is widely regarded as a key textbook in the field of international relations and is also seen as the central text in the so-called 'English School' of international relations. In this book, he argues that despite the anarchical character of the international arena, it is characterised by the formation of not only a system of states, but a society of states. His requirements for an entity to be called a state are that it must claim sovereignty over (i) a group of people (ii) a defined territory, and that it must have a government. States form a system when they have a sufficient degree of interaction, and impact on each other's decisions, so as they "behave — at least in some measure — as parts of a whole." A system of states can exist without it also being a society of states. A society of states comes into existence "when a group of states, conscious of certain common interests and common values, form a society in the sense that they conceive themselves to be bound by a common set of rules in their relations with one another, and share in the working of common institutions."

The society of states is a way for Bull to analyse and assess possibilities of order in world politics. He continues his argument by giving the concept of order in social life, and the mechanisms of: the balance of power, international law, diplomacy, war and the great powers central roles. He finally concludes that, despite the existence of possible alternative forms of organization, the states system is our best chance of achieving order in world politics.