All University PhD and MPhil theses are available via the library catalogue. Masters theses for some subjects are held in the Library for 6 years. 

All York research students registered in or after October 2009 are required to upload their thesis into the White Rose Research Online, a shared online respository for academic publications from the Universities of York, Sheffield and Leeds.

You can also access theses from outside the University:

• British Library EThOS Service
  The British Library's electronic online theses service. Free access to over 300,000 full-text theses from UK universities.
• DART-Europe E-these Portal
  A searchable database of details of doctoral-level electronic theses which are held in European repositories. The DART-Europe Portal does not store theses, but it provides a link to at least one electronic copy of every thesis listed in its database.
• Index to Theses
  A comprehensive listing of theses with abstracts accepted for higher degrees by universities in the United Kingdom and Ireland since 1716. Currently 576,832 theses in collection (343,680 of which have abstracts). May 2012.
• Networked Digital Library of Theses and Dissertations
  Use for searching for international theses.