| Abbreviation | Definition |
|---|---|
| UA4A | United Action for Animals |
| UAA | United Action for Animals |
| UAA | Urban Affairs Association |
| UAA | Uyghur American Association |
| UAC | United American Committee |
| UAD | Utah Association for the Deaf |
| UAEA | University Area Enrichment Association |
| UAH | Utahns Against Hunger |
| UAI | Association for Uncertainty in Artificial Intelligence |
| UAI | Union des Associations Internationales |
| UAN | United Animal Nations |
| UAS | United Armenian Students |
| UBF | United Black Fund |
| UBFA | United Black Fund, Inc., of America |
| UBFI | United Black Fund, Inc. |
| UBFIGW | United Black Fund, Inc., of Greater Washington |
| UBFOAI | United Black Fund Of America, Inc. |
| UBN | United Bear Network |
| UC | Union Club |
| UCA | United Cheerleaders of America |