Columbia University Oral History Office
The resources page is an excellent place to identify major repositories of oral history collections.
International Oral History Association
"A professional association established to provide a forum for oral historians around the world, and a means for cooperation among those concerned with the documentation of human experience. "
Oral Histories Online
This subscription database from Alexander Street Press provides in-depth indexing to more than 2,700 collections of Oral History in English from around the world.
Oral History Collections: Tamiment & Robert F. Wagner Labor Archives (NYU)
The Tamiment Library holds more than 80 oral history collections containing hundreds of interviews with labor leaders, rank-and-file workers, and political activists; audio tapes of speeches, concerts, conferences, memorial meetings, union meetings and other public and private events; and commercial recordings such as radio broadcasts.
Oral History Project: Labor History (Roosevelt University)
Transcripts of 68 labor-related oral history interview's with Chicago area workers
WorldCat
Using the Advanced search, limit the format to "sound recordings" then search on "oral history" under Keyword to find oral history collections. Add additional Author or Subject terms to focus results.