| X -klasse | X class submarine |
| X Factor | The X Factor |
| X Games | X Games |
| X Japan | X Japan |
| X Window System | Porn actor |
| x-benen | knock-knees |
| X-chromosoom | X-chromosome |
| X-Factor | X-Factor |
| X-Men | X-Men |
| X-stralen | X-rays |
| X-Wing | X-wing |
| Xabi Alonso | Xabi Alonso |
| Xabier Prieto | Xabier Prieto |
| Xabier Zandio | Xabier Zandio |
| Xagħra | Xagħra |
| Xalapa de Enríquez | Xalapa |
| XAML | Extensible Application Markup Language |
| Xanadu | Xanadu |
| Xanana Gusmão | Xanana Gusmão |
| Xandros Desktop OS | Xandros |
| Xanten | Xanten |
| Xanthi | Xanthi |
| xanthine | xanthine |
| Xanthippe | Xanthippe |
| Xanthippus | Xanthippus of Carthage |
| Xanthorrhoea | Xanthorrhoea |
| Xanthus en Balius | Balius and Xanthus |
| Xavante | Xavante |
| Xaverius | Xavier |
| Xavi Hernández | Xavi |
| Xavier Bichat | Marie François Xavier Bichat |
| XBM | X BitMap |
| Xbox | Xbox |
| XChat | XChat |
| XD-Picture Card | XD-Picture Card |
| Xe arrondissement | Xe arrondissement |
| Xenarthra | Xenarthra |
| Xenia Aleksandrovna van Rusland | Grand Duchess Xenia Alexandrovna of Russia |
| Xenix | Xenix |
| xeno- | xeno- |
| Xenofilie | Xenophily |
| xenofobie | xenophobia |
| xenofobisch | xenophobic |
| xenofoob | xenophobic |
| xenon | xenon |
| Xenophanes | Xenophanes |
| Xenophon | Xenophon |
| Xenophon van Efese | Xenophon of Ephesus |
| Xenotarsosaurus | Xenotarsosaurus |
| xenotransplantatie | xenotransplantation |
| Xenoturbellida | Xenoturbella |
| Xenu | Xenu |
| Xeon | Xeon |
| Xeraco | Xeraco |
| Xerces | Xerces |
| Xerez CD | Xerez CD |
| Xermade | Xermade |
| Xerox Supercup | Japanese Super Cup |
| Xerta | Xerta |
| Xerxes | Xerxes |
| Xerxes I | Xerxes I of Persia |
| Xerxes II | Xerxes II of Persia |
| Xewkija | Xewkija |
| Xfce | Xfce |
| Xhosa | Xhosa |
| Xhosa- | Xhosa |
| Xhosataal | Xhosa |
| Xhosavrouw | Xhosa woman |
| XHTML Mobile Profile | XHTML Mobile Profile |
| xi | xi |
| Xi en He | Xihe |
| Xi Jiang | Xijiang River |
| Xi Shun | Bao Xishun |
| Xia Jie | Jie of Xia |
| Xia Qi | Qi of Xia |
| Xia Yu | Yu the Great |
| Xia-dynastie | Xia Dynasty |
| Xiamen | Xiamen |
| Xianbei | Xianbei |
| Xianfeng | Xianfeng Emperor |
| Xiang Sun | Sun Xiang |
| Xiangfan | Xiangfan |
| Xiantianisme | Way of Former Heaven |
| Xianyang | Xianyang |
| Xicheng-district | Xicheng District |
| XIe arrondissement | XIe arrondissement |
| Xie Jun | Xie Jun |
| Xie Xingfang | Xie Xingfang |
| Xigazê | Shigatse |
| XIIe arrondissement | XIIe arrondissement |
| XIIIe arrondissement | XIIIe arrondissement |
| Xin | Xin |
| Xindi | Xindi |
| Xing Huina | Huina Xing |
| Xing Yi Quan | Xingyiquan |
| Xingu | Xingu River |
| Xining | Xining |
| Xinjiangovenator | Xinjiangovenator |
| XInput | DirectInput |
| Xinzo de Limia | Xinzo de Limia |
| Xiong Nu | Xiongnu |
| Xipe Totec | Xipe Totec |
| Xirivella | Xirivella |
| Xisco Muñoz | Francisco Javier Muñoz |
| Xishuangbanna | Xishuangbanna Dai Autonomous Prefecture |
| Xiuhtecuhtli | Xiuhtecuhtli |
| XIVe arrondissement | XIVe arrondissement |
| XIXe arrondissement | XIXe arrondissement |
| XL | XL |
| XLR | XLR connector |
| XML Query Language | XQuery |
| XML Schema Definitietaal | XML Schema |
| XMLHTTP | XMLHttpRequest |
| XMMS | XMMS |
| XMP | Extensible Metadata Platform |
| XNA | Microsoft XNA |
| XNOR-poort | Logical equality |
| Xochimilco | Xochimilco |
| Xochipilli | Xochipilli |
| Xochiquetzal | Xochiquetzal |
| Xolotl | Xolotl |
| Xonotliet | Xonotlite |
| XOOPS | XOOPS |
| XOR-poort | XOR gate |
| XQuery | XQuery |
| XSL Formatting Objects | XSL Formatting Objects |
| Xu Yuhua | Xu Yuhua |
| Xuande | Xuande Emperor |
| Xuanhua | Xuanhua District |
| Xuanhuaceratops | Xuanhuaceratops |
| Xuanwu-district | Xuanwu District |
| Xuanzang | Xuanzang |
| Xujiahui | Xujiahui |
| XUL | XUL |
| Xunqueira de Ambía | Xunqueira de Ambía |
| Xunqueira de Espadanedo | Xunqueira de Espadanedo |
| Xuzhou | Xuzhou |
| XVe arrondissement | XVe arrondissement |
| XviD | Xvid |
| XVIe arrondissement | XVIe arrondissement |
| XVIIe arrondissement | XVIIe arrondissement |
| XVIIIe arrondissement | XVIIIe arrondissement |
| XXe arrondissement | XXe arrondissement |
| xyleem | xylem |
| Xylenol | Xylenol |
| xylofoon | xylophone |
| xylografie | xylography |
| Xylokastro | Xylokastro |
