The Oxford University Society (OUS) is the official alumni organisation of the University of Oxford. It is an autonomous charitable company, limited by guarantee. Its object is the advancement of the purposes and interests of the University of Oxford. All who have matriculated at the University, or who have engaged in academic work in the University or in any college, are eligible to register for membership. There is no subscription.

The Society encourages closer relations between its members and the collegiate University by supporting a worldwide network of autonomous Branches run by volunteers. The Branches organise local events, usually with an educational, intellectual, and enjoyable social dimension, and frequently with a prominent local Oxonian or visitor from Oxford as speaker. Events help to bring members together and keep them better informed about the contemporary University.

Oxford University Society has international branches too.