The Open University (OU) is a public distance learning and research university, and one of the biggest universities in the UK for undergraduate education. The majority of the OU's undergraduate students are based throughout the United Kingdom and principally study off-campus; many of its courses (both undergraduate and postgraduate) can also be studied anywhere in the world. There also are a number of full-time postgraduate research students based on the 48-hectare university campus where they use the OU facilities for research, as well as more than 1000 members of academic and research staff and over 2500 administrative, operational and support staff.
The OU was established in 1969 and the first students enrolled in January 1971. The University administration is based at Walton Hall, Milton Keynes in Buckinghamshire, but has regional centres in each of its thirteen regions around the United Kingdom. It also has offices and regional examination centres in many other European countries. The university awards undergraduate and postgraduate degrees, as well as non-degree qualifications such as diplomas and certificates or continuing education units.
With more than 250,000 students enrolled, including around 32,000 aged under 25 and more than 50,000 overseas students, it is the largest academic institution in the United Kingdom (and one of the largest in Europe) by student number, and qualifies as one of the world's largest universities. Since it was founded, more than 1.5 million students have studied its courses.