- O'Shaughnessy Family Papers, 1857/196522
- O.D. Linder, Compiler, Genealogy Records Regarding the Boyce, Dever, Gibson, and Linder Families, 1860/2000, bulk 1900/20001
- O.J. Morrison Department Stores Company (West Virginia and Ohio) Records, 1910/1985, bulk 1940/19501
- O.W. Riegel Papers, 1900/1992822
- Oak Grove Baptist Church Records, 1853/19591
- Obituaries of Ritchie and Tyler County Residents, 1947/20141
- Ocean View, Seaside, and Seaview Amusement Parks Collection, 1919/1991, bulk 1940/197947
- Office of Admission records, 1861/20213
- Office of Alumni Engagement records3
- Office of Communications and Marketing audio and video collections1
- Office of Communications and Marketing subject files, 195081
- Office of Communications and Public Affairs records, 1948/200212
- Office of Educational Media, 1947/19842
- Office of Institutional Research and Assessment Records, 1940/20092
- Office of Planning and Budget Records, 1948/19901