From 1918 to 1970, much of the seat now known as Witney was classed as part of the Banbury Constituency which included Banbury, Chipping Norton and Woodstock as well. From 1971 to 1983, the area was included in Mid-Oxfordshire along with parts of Bullingdon and Ploughley. Since 1983, Witney has been a full Parliamentry Seat in its own right and comprises the whole of the District of West Oxfordshire plus two villages close to Oxford which are in the Cherwell District Council Area.

It is typically made up of market towns of which Witney is the largest with a population of 23,000 and others include Chipping Norton with 6000 and Woodstock with 4000. Carterton is the second largest population centre with 14,000, and is situated alongside RAF Brize Norton which is vital to the local economy being one of the largest and busiest RAF bases in the country. The balance is very rural and it is the largest area in all of the Districts in the County of Oxfordshire. The industrial profile has changed radically over the past few decades from predominantly agricultural and blanket based to the present day with many smaller hi-tech businesses such as those involved in high performance Formula 1 racing cars, computer technology and associated services. At the same time there has been a rapid expansion in the entire tourism industry in this area with visitors coming from all over the world.