- Office of Alumni Engagement records1
- Office of the Bursar Records, 1739/198710
- Office of the President Timothy J. Sullivan records, 1992/2005, bulk 1992/20051
- Office of the President. James Blair Records, 1695/17471
- Ohio County (W. Va.) Court Records and Miscellaneous Papers, 1772/1954, bulk 1777/19305
- Ollen Lawrence Burnette, Jr. papers, 1815/20141
- Ollinger Crenshaw Papers, 1770/19703
- Orum, Eskey, and McCaffery Family Papers, 1746/20181
- Oscar Doane Lambert, Historian, Papers regarding Historical Research, 1770/19291
- Oscar Shewmake Autograph Collection, 1766/18132
- Overton family papers, 1727/1961, bulk 1781/187511