Oxford Tube, frequent times, 100 minutes from London to Oxford. Drop at St Clements stop and it is a 10 minutes walk.
Frequent direct trains travel from London Paddington, Birmingham New Street, Manchester Piccadilly and Liverpool Lime Street. The journey time takes approx. 1hr from London. Many visitors prefer to take the speedier option of a taxi from the station to either the High Street or Bullingdon Road, however buses are also available from the station. You need to ask for the Cowley Road stop.