You can search for Oxford MPhil and DPhil theses on SOLO. Simply search for "oxford thesis" plus other significant keywords such as 'Oxfordshire' or specific place name together with any other subject keywords. DPhil theses can be requested on SOLO from the Bodleian Bookstack to the Weston Library for consultation. Some recent theses may be available online on ORA (Oxford Research Archive) These will also be listed on SOLO.
Dissertations written by Continuing Education students are available for consultation in the Rewley House Continuing Education Library . Recent years are shelved under the stairs in the Lower Library, ask staff for older titles. A list of titles held is available in the Library.
Many of these dissertations are also listed in:
Oxford University Local History Dissertations 1980-2005 /Kate Tiller. 941.0072 TIL (Local Collection Pamphlet). This is an offprint from Oxoniensia v.LXXI 2006
EThOS lists British doctoral theses, providing online access to many of them.
Worldwide Dissertations and Theses
Dissertations and Theses contains details of theses from around the world dating back to 1637, many of which are available in full text.
For more information about finding theses, see the Bodleian Libraries website.