| Xi Boötis | Xi Boötis |
| Xi Puppis | Asmidike |
| Xi Ursae Majoris | Xi Ursae Majoris |
| Xia | XIA |
| Xia Dynasty | Dinastia Xia |
| Xiamen | Xiamen |
| Xiang | Lingua xiang |
| Xiangkhoang Province | Xiangkhoang |
| Xiangtan | Xiangtan |
| Xiaolin Showdown | Xiaolin Showdown |
| Xiazhi | Solstizio |
| Xibe | Xibe |
| XIe arrondissement | XI arrondissement di Parigi |
| Xie Jun | Xie Jun |
| Xiehouyu | Proverbi cinesi |
| XIIe arrondissement | XII arrondissement di Parigi |
| XIIIe arrondissement | XIII arrondissement di Parigi |
| Xijiang River | Xi Jiang |
| Xilinhot | Abagnar Qi |
| Xindi | Xindi |
| Xingu | Xingu |
| Xingu National Park | Parque Indígena do Xingu |
| Xingu River | Xingu |
| Xingyiquan | Xingyiquan |
| Xining | Xining |
| Xinjiang | Xinjiang |
| Xinzo de Limia | Xinzo de Limia |
| Xiongnu | Xiongnu |
| Xipe Totec | Xipe Totec |
| Xiphos | Xiphos |
| xiphosauran | xifosuro |
| Xirivella | Xirivella |
| Xiuhcoatl | Xiuhcoatl |
| Xiuhtecuhtli | Xiuhtecuhtli |
| XIVe arrondissement | XIV arrondissement di Parigi |
| XIXe arrondissement | XIX arrondissement di Parigi |
| XL | XL |
| XLR connector | Connettore XLR |
| Xmas | Natale |
| XML | XML |
| XML - Managing Data Exchange | Programmare in XML |
| XML Metadata Interchange | XML Metadata Interchange |
| XML Namespace | Namespace |
| XML Schema | XML Schema |
| XML Schema Definition | XML Schema |
| XMLHttpRequest | XMLHttpRequest |
| XMM-Newton | XMM-Newton |
| XMMS | XMMS |
| XMPP | Jabber |
| Xo Dang people | Xo Dang |
| xoanon | xoanon |
| Xochimilco | Xochimilco |
| Xochipilli | Xochipilli |
| Xochiquetzal | Xochiquetzal |
| Xois | Xois |
| Xolotl | Xolotl |
| Xonotlite | Xonotlite |
| Xonrupt-Longemer | Xonrupt-Longemer |
| XOOPS | XOOPS |
| XOOPS Cube | XOOPS |
| XOR gate | Disgiunzione esclusiva |
| XOR swap algorithm | Swap |
| Xorking plane | Piano di lavorazione |
| XPCOM | XPCOM |
| XPDL | XPDL |
| XQuery | XQuery |
| XS | XS |
| XScale | XScale |
| Xserve | Famiglia Xserve |
| Xserve RAID | Famiglia Xserve RAID |
| XSL Formatting Objects | XSL-FO |
| XSL Transformations | XSL Transformations |
| Xuanhanosaurus | Xuanhanosaurus qilixiaensis |
| Xuanzang | Xuanzang |
| Xucuru | Xucuru-Kariri |
| XUL | XUL |
| Xun Zi | Sun Tzu |
| Xunqueira de Ambía | Xunqueira de Ambía |
| Xunqueira de Espadanedo | Xunqueira de Espadanedo |
| Xuthus | Xuto |
| XVe arrondissement | XV arrondissement di Parigi |
| Xvid | XviD |
| XVIe arrondissement | XVI arrondissement di Parigi |
| XVIIe arrondissement | XVII arrondissement di Parigi |
| XVIIIe arrondissement | XVIII arrondissement di Parigi |
| XXe arrondissement | XX arrondissement di Parigi |
| XxxHolic | XxxHOLiC |
| xylan | xylano |
| xylanase | xilanasi |
| xylem | xilema |
| Xylem Tube EP | Xylem Tube EP |
| xylene | xilene |
| xylo- | xilo- |
| Xylocopinae | Xylocopinae |
| xylograph | xilografia |
| xylophone | xilofono |
| xylose | xilosio |
