- Tate Thompson Brady Family papers, 1785/20059
- Tax reports of public service corporations from the State Corporation Commission,, 1895/20151
- Temple Beth El scrapbooks, 1959/20096
- Tercentenary Records, 1987/1993238
- Terrill-Porterfield Families, Papers regarding the Civil War and Other Material, 1716/1994, bulk 1840/19201
- Terry Burton, Collector, Ogden House Collection, 1886/19971
- Terry L. Meyers papers, 1988/20106
- Thad W. Tate papers, 1949/20092
- Thaddeus Podratsky, Collector, Records Regarding the Socialist Party, 1911/2006, bulk 1911/19371
- The Center for Nursing Historical Inquiry collection, 1934/200123
- The Charles Baptie photograph collection, 1917/19959
- The Edgar Cayce Readings, 1886-20201
- The Eric Shoaf Tom Wolfe collection1
- The Fairfax County Office of Comprehensive Planning Heritage Resources Branch Slide Collection,
1967-19932
- The Flat Hat records, 1911/20192