The May ball is an event particularly associated with the Universities of Oxford and Cambridge. In Oxford it is known as the Commemoration ball or Commem. because it is usually held around the same time as the university Encaenia (or Commemoration of benefactors). Some other educational establishments have also adopted the practice.

Many individual colleges of the universities host balls which originally were held during the month of May, but now often occur in June following the end of exams (in Cambridge, May Balls start in the week following Suicide Sunday, which is usually the second Sunday in June). Such events typically last all night (9pm to 6am) and include dinner and a selection of different types of entertainment, which may include classical music, rock bands, magicians, fireworks, etc. They are usually very expensive to attend (prices range from £80 to £140 per single ticket depending on whether guests wish to eat at the formal meal), and require formal evening dress. Irrespective of whether guests have decided to eat at the formal meal, balls will usually provide free food and drink all night.