Theses repositories

EThOS - UK Theses. 
EThOS is a British Library service providing full text access (where available) to theses from UK institutions, linking either directly from EThOS or via a link to the repository of the awarding institution.

It is free of charge to join, but you need to register for an account in order to download theses. Theses that are not currently available full text can be requested, but may incur a fee. Not all UK universities take part in EThOS (notably Oxford and Cambridge), but if you require a doctoral thesis from one of these institutions, please contact Interlibrary@abertay.ac.uk

DART-Europe E-Theses Portal - European Theses.
DART-Europe eTheses Portal is a partnership of research libraries and library consortia who are working together to improve global access to European research theses from over 600 institutions from 28 countries.

PQDT Open - mainly US Theses.
PQDT Open provides the full text of open access dissertations and theses free of charge. 

Ebsco Open Dissertations
An Ebsco tool that searches for international open access dissertations and theses free of charge.

Other Useful Resources

If you need more help finding specific theses and dissertations, please contact your Academic Librarian.