Passing a street of Oxford University by car, Oxford, Oxfordshire, UK. Oxford is a city in central Southern England. It is the county town of Oxfordshire and forms a district within the county. It has a population of 150,200, which makes it the 52nd largest city in the UK and lies within the Oxford metropolitan area with a population of 244,000.Oxford is one of the UK's fastest growing cities, in terms of population.Oxford has a diverse economic base.The city is known worldwide as a university town and home of the University of Oxford, the oldest university in the country. Buildings in Oxford demonstrate examples of every English architectural period since the arrival of the Saxons.