International Dialects of English Archive (IDEA)
Internet’s first archive of primary-source recordings of English-language dialects and accents from around the world. It’s the largest archive of its kind and includes native and non-native speakers of English. Comprehensive and very useful.
British Library Sounds – Accents and Dialects
Includes British dialects, accents from around the world, BBC recordings, early spoken word recordings, and so much more.
Click on the individual words to hear the differences in pronunciations by region, country, city, and certain specific dialects
North American English Dialects, Based on Pronunciation Patterns
YouTube links will take you to video samples of American English dialects, with a few Canadian thrown in for good measure.
Words and some sentences recorded by speakers, identified only generally by country, but can be quite useful.
University of Wisconsin – Madison
Field recordings of native residents from all 50 states and DC, collected between 1965 and 1970. They visited native residents in all fifty states and D.C.
Erik Singer Videos
Dialect coach Erik Singer (with whom I coached before creating the General American Accent workshop) takes us on a tour of different accents across English-speaking North America. Informative and fun.
Part 1 - https://youtu.be/H1KP4ztKK0A
Part 2 - https://youtu.be/IsE_8j5RL3k
Part 3 - https://youtu.be/Sw7pL7OkKEE