- S. Bassett French Papers (I) and (II), 1858/18921
- S. Bassett French Papers (II), 1872/18931
- S. Maria Elliott Family Collection, 1826/19422
- Sabra Lucinda (Miner) Sturgiss Papers, 1838/19091
- Saint Andrew's Society collection, 1861/19956
- Sallie Bennett Papers regarding World War I Flying Ace Louis Bennett, Jr., 1873/2009, bulk 1904/19262
- Salt Sulphur Springs Records, 1819/19321
- Salt Sulphur Springs Records, 1825/18831
- Sam Bowman Papers, 1848/19672
- Sam di Bonaventura papers, 1900/19982
- Sampson Snider Civil War Records and Other Material, 1864/19051
- Samuel A. Creelman Papers, 1861/19062
- Samuel B. Finley Account Books, 1802/18591
- Samuel D. Morton and Co. Account Books, 1826/18914
- Samuel Davidson Family Papers, 1823/19396