Collection
- Olga Larson Collection, 1892-19651
- Olin Norwood Collection, 1621-1945, Date acquired: 03/28/19561
- Olive Campbell papers, 1897-1952, bulk 1906-19191
- Orchestral Dance Music Collection, 1890-19601
- Ormsby Family Collection, 1856-19331
- Orwin Rush Newspaper Collection, 1861-1920, bulk 1860-18691
- Papers of Thomas Y. King And Arthur King, 1898-1958, Date Acquired1
- Parsons collection of Peter Demens and the two St. Petersburgs (Florida and Russia), bulk 1890-20051
- Paul A.M. Dirac Papers, 1788-19991
- Paul Dosal Cuban Tourism collection, 1879-1961, Date acquired: 04/17/2015, bulk 1879- 19611
- Paul S. Thomson Insurance ledgers, 1899-19131
- Paul and Mary Rosen Collection, Circa 1900-20001
- Pfeiffer Family Papers, 1891-1963, Date acquired: 02/00/19841
- Philip Keyes Yonge Collection, 1907-1932, bulk 1907-19321
- Phipps Family papers, 1854-19591
- Photograph albums, 1907-1918, Date acquired: 06/00/19991
- Photographic lantern slide collection, 1902-1929, Date acquired: 00/00/19951
- Pine Hill Plantation Papers, 1832-1926, Date acquired: 07/31/19651
- Plant Railway system records, 1874-1922, Date acquired: 00/00/1984, bulk 1878-19001
- Pleas, Charles Earl, Papers, 1867-1954, Date acquired: 06/00/19701