| Trakehner Name | Sex | Foaled | Sire | Dam | Color | |
|---|---|---|---|---|---|---|
| Under Orders xx | Stallion | Unknown | Unknown | |||
| Understudy xx | Stallion | Unknown | Unknown | |||
| Under The Rainbow | Mare | 1984 | Donauschimmer | Undine | dark bay/brown | |
| Undine | Mare | 1979 | Ibikus | Urtica | chestnut | |
| Unequaled xx | Mare | Unknown | Unknown | |||
| Unesco | Stallion | 1975 | Kassius | Udine | chestnut | |
| Unfold xx | Stallion | Unknown | Unknown | |||
| Ungewitter | Mare | 1990 | Schönfeld *E* | Umberland xx | bay (gray) | |
| Unicrose xx | Mare | Unknown | Unknown | |||
| Unicum 9 | Gelding | 1996 | Handryk | Urbana | chestnut | |
| Uninhibited | Stallion | 1991 | Unabkömmlich | Sweet Honesty xx | bay (gray) | |
| Union Blue xx | Mare | Unknown | Unknown | |||
| Unique | Mare | 1989 | Unkenruf *Pg*E* | Donja | chestnut | |
| Unique Sonata | Mare | Unknown | Unknown | |||
| Universal | Stallion | Utraschall | Lagune | |||
| Unkas | Gelding | 1999 | E.H. Louidor | Utimor (St.Pr.St.) | bay | |
| Unkenlied | Mare | Donauwind *E* | Ultima | |||
| Unkenruf *Pg*E* | Stallion | 1970 | Donauwind *E* | Ultima | chestnut | |
| Unkensee | Stallion | 1978 | Karneval II | Unkenspiel | bay | |
| Unkenspiel | Mare | Tannenberg *E* | Unkenlied | brown | ||
| unknown | Stallion | Unknown | Unknown | |||
| Unknown | Unknown | Unknown | ||||
| UNKNOWN | Stallion | Unknown | Unknown | |||
| Unna | Mare | 1978 | Istanbul | Uta II | brown/black | |
| Unsergeist | Stallion | 1981 | Preussengeist *E* | Samantha | chestnut |