| X arrondissement di Parigi | Xe arrondissement |
| X dinastia egizia | Tenth dynasty of Egypt |
| X Division | X Division |
| X Football League | XFL |
| X Japan | X Japan |
| X Prize Foundation | X Prize Foundation |
| X Window System | Porn actor |
| X-Factor | X-Factor |
| X-Files | The X-Files |
| X-Files - Il film | The X-Files |
| X-Men | X-Men |
| X-wing | X-wing |
| Xabi Alonso | Xabi Alonso |
| Xai-Xai | Xai-Xai |
| Xaignabouli | Xaignabouli Province |
| Xaisomboun | Xaisomboun |
| XAML | Extensible Application Markup Language |
| Xanadu | Xanadu |
| Xanana Gusmão | Xanana Gusmão |
| Xanatos | Xanatos |
| Xander Harris | Xander Harris |
| Xandrianesimo | Alexandrian Wicca |
| XANES | X-ray absorption spectroscopy |
| Xanten | Xanten |
| xantenico | xanthenic |
| Xanthi | Xanthi |
| Xanthos | Xanthos |
| xantina | xanthine |
| xantogenato | xanthogenate |
| xantomatoso | xanthomous |
| Xavante | Xavante |
| Xavi | Xavi |
| Xavier Sala i Martín | Xavier Sala-i-Martin |
| Xbill | XBill |
| XChat | XChat |
| XD-Picture Card | XD-Picture Card |
| XE | Xe |
| Xedos | Xedos |
| Xekong | Xekong Province |
| Xena | Xena |
| Xenartha | Xenarthra |
| Xenarthra | Xenarthra |
| xenartro | xenarthran |
| Xenia | Xenia |
| Xenia di San Pietroburgo | Xenia of Saint Petersburg |
| Xenicus lyalli | Stephens Island Wren |
| xeno | xenon |
| xenobio | xenobiont |
| xenobionte | xenobiont |
| xenobiotico | xenobiotic |
| xenocidio | xenocide |
| xenodochio | xenodochium |
| xenofobia | xenophobia |
| xenofobo | xenophobic |
| Xenoglossia | Xenoglossy |
| Xenomorfo | Xenomorph |
| xenon | xenon |
| Xenopeltis unicolor | Xenopeltis unicolor |
| Xenophon Zolotas | Xenophon Zolotas |
| xenopo | African clawed frog |
| Xenotarsosaurus bonapartei | Xenotarsosaurus |
| xenotima | xenotime |
| xenotrapianto | xenotransplantation |
| Xenu | Xenu |
| Xeon | Xeon |
| Xeraco | Xeraco |
| Xeresa | Xeresa |
| Xerez Club Deportivo | Xerez CD |
| Xeriscaping | Xeriscaping |
| Xermade | Xermade |
| Xerocomus | Xerocomus |
| Xerocomus badius | Boletus badius |
| xerocopiare | copy |
| xeroderma | xeroderma |
| xeroftalmia | xerophthalmia |
| xeroradiografia | xeroradiography |
| Xerox Alto | Xerox Alto |
| Xerox Corporation | Xerox |
| Xerox Palo Alto Research Center | PARC |
| Xerta | Xerta |
| Xeuchia | Xewkija |
| Xfce | Xfce |
| Xgl | Xgl |
| xhosa | Xhosa |
| XHTML | XHTML |
| XHTML Mobile Profile | XHTML Mobile Profile |
| Xi | Xi |
| XI arrondissement di Parigi | XIe arrondissement |
| Xi Boötis | Xi Boötis |
| XI dinastia egizia | Eleventh dynasty of Egypt |
| Xi Jiang | Xijiang River |
| Xi Ursae Majoris | Xi Ursae Majoris |
| XIA | Xia |
| Xiamen | Xiamen |
| Xian | Sennin |
| Xiangkhoang | Xiangkhoang Province |
| Xiangtan | Xiangtan |
| Xiantiandao | Way of Former Heaven |
| Xiaolin Showdown | Xiaolin Showdown |
| Xibe | Xibe |
| Xie Jun | Xie Jun |
| xifosuro | xiphosauran |
| XII arrondissement di Parigi | XIIe arrondissement |
| XII dinastia egizia | Twelfth dynasty of Egypt |
| XIII arrondissement di Parigi | XIIIe arrondissement |
| XIII dinastia egizia | Thirteenth dynasty of Egypt |
| xilanasi | xylanase |
| xilano | xylan |
| xilema | xylem |
| xilene | xylene |
| xilo- | xylo- |
| xilofono | xylophone |
| xilografia | xylograph |
| xilosio | xylose |
| XIN | Xin |
| Xindi | Xindi |
| Xingu | Xingu River |
| Xingyiquan | Xingyiquan |
| Xining | Xining |
| Xinjiang | Xinjiang |
| Xinjiang Uygur | Xinjiang |
| Xinzo de Limia | Xinzo de Limia |
| Xiongnu | Xiongnu |
| Xipe Totec | Xipe Totec |
| Xiphophorus helleri | Green swordtail |
| Xiphophorus variatus | Variable platyfish |
| Xiphos | Xiphos |
| Xirivella | Xirivella |
| Xiuhcoatl | Xiuhcoatl |
| Xiuhtecuhtli | Xiuhtecuhtli |
| XIV arrondissement di Parigi | XIVe arrondissement |
| XIV dinastia egizia | Fourteenth dynasty of Egypt |
| XIX arrondissement di Parigi | XIXe arrondissement |
| XIX dinastia egizia | Nineteenth dynasty of Egypt |
| Xizor | Prince Xizor |
| XL | XL |
| Xmas | Xmas |
| XML | XML |
| XML Metadata Interchange | XML Metadata Interchange |
| XML Schema | XML Schema |
| XMLHttpRequest | XMLHttpRequest |
| XMM-Newton | XMM-Newton |
| XMMS | XMMS |
| Xo Dang | Xo Dang people |
| xoanon | xoanon |
| Xochimilco | Xochimilco |
| Xochipilli | Xochipilli |
| Xochiquetzal | Xochiquetzal |
| Xois | Xois |
| Xolotl | Xolotl |
| Xonotlite | Xonotlite |
| Xonrupt-Longemer | Xonrupt-Longemer |
| XOOPS | XOOPS |
| XOXO | Hugs and Kisses |
| XPCOM | XPCOM |
| XPDL | XPDL |
| XQuery | XQuery |
| XS | XS |
| XScale | XScale |
| XSL | Extensible Stylesheet Language |
| XSL Transformations | XSL Transformations |
| XSL-FO | XSL Formatting Objects |
| Xuan Zong | Emperor Xuanzong of Tang |
| Xuanhanosaurus qilixiaensis | Xuanhanosaurus |
| Xuanzang | Xuanzang |
| Xucuru-Kariri | Xucuru |
| XUL | XUL |
| Xunqueira de Ambía | Xunqueira de Ambía |
| Xunqueira de Espadanedo | Xunqueira de Espadanedo |
| Xuto | Xuthus |
| XV arrondissement di Parigi | XVe arrondissement |
| XV dinastia egizia | Fifteenth dynasty of Egypt |
| XVI arrondissement di Parigi | XVIe arrondissement |
| XVI dinastia egizia | Sixteenth dynasty of Egypt |
| XviD | Xvid |
| XVII arrondissement di Parigi | XVIIe arrondissement |
| XVII dinastia egizia | Seventeenth dynasty of Egypt |
| XVIII arrondissement di Parigi | XVIIIe arrondissement |
| XVIII dinastia egizia | Eighteenth dynasty of Egypt |
| XX arrondissement di Parigi | XXe arrondissement |
| XX dinastia egizia | Twentieth dynasty of Egypt |
| XXI dinastia egizia | Twenty-first dynasty of Egypt |
| XXII dinastia egizia | Twenty-second dynasty of Egypt |
| XXIII dinastia egizia | Twenty-third dynasty of Egypt |
| XXIV dinastia egizia | Twenty-fourth dynasty of Egypt |
| XXIX dinastia egizia | Twenty-ninth dynasty of Egypt |
| XXV dinastia egizia | Twenty-fifth dynasty of Egypt |
| XXVI dinastia egizia | Twenty-sixth dynasty of Egypt |
| XXVII dinastia egizia | Achaemenid dynasty |
| XXVIII dinastia egizia | Twenty-eighth dynasty of Egypt |
