| Tetracladia Howard, 1892 |
| Tetracnemella Girault, 1915 |
| Tetracneminae Howard, 1892 |
| Tetracnemoidea Compere, 1939 |
| Tetracnemoidea peregrina Compere, 1939 |
| Tetracnemus Westwood, 1837 |
| Tetracnemus ashmeadi Noyes & Woolley, 1994 |
| Tetracnemus floridanus (Ashmead, 1887) |
| Tetralophidea Ashmead, 1900 |
| Tetralophiellus Ashmead, 1900 |
| Therencyrtus Trjapitzin, 1977 |
| Thysanomastix R.C.L. Perkins, 1907 |
| Timberlakia Mercet, 1925 |
| Tongyus Noyes & Hayat, 1984 |
| Trichomasthus Thomson, 1876 |
| Trichomasthus farfani Trjapitzin & Ruiz-Cancino, 2001 |
| Trichomasthus mexicanus (Girault, 1917) |
| Trjapitzinellus Viggiani, 1967 |
| Trjapitzinellus microrphanos Gordh, 1973 |
| Tyndarichoides Mercet, 1921 |