| x-axel | x-axis |
| X-COM | X-COM series |
| X-enhet | X unit |
| X-Japan | X Japan |
| X-krok | picture hook |
| X-kromosom | X-chromosome |
| X-Men | X-Men |
| X-Moto | X-Moto |
| X-strålar | X-rays |
| X-Wing | X-wing |
| Xabi Alonso | Xabi Alonso |
| Xai-Xai | Xai-Xai |
| XAML | Extensible Application Markup Language |
| Xanadu | Xanadu |
| Xanana Gusmão | Xanana Gusmão |
| Xanatos | Xanatos |
| Xandros | Xandros |
| Xanten | Xanten |
| Xanthi | Xanthi |
| Xanthippos | Xanthippus of Carthage |
| xantippa | shrew |
| Xavi | Xavi |
| Xavier | Xavier |
| XBoard | XBoard |
| Xbox Live Marketplace | Xbox Live Marketplace |
| Xbox Live Vision Camera | Xbox Live Vision |
| XChat | XChat |
| XD-Picture Card | XD-Picture Card |
| XDM | XDM |
| Xedos | Xedos |
| Xen | Xen |
| Xena - Krigarprinsessan | Xena |
| Xenia av Sankt Petersburg | Xenia of Saint Petersburg |
| Xenix | Xenix |
| xenofobi | xenophobia |
| Xenofon | Xenophon |
| Xenoglaux loweryi | Long-whiskered Owlet |
| xenon | xenon |
| Xenontrioxid | Xenon trioxide |
| Xenophanes | Xenophanes |
| xenotransplantation | xenotransplantation |
| Xenozoicum | Xenozoic Tales |
| Xenu | Xenu |
| Xeon | Xeon |
| Xerez CD | Xerez CD |
| XeroBank Browser | XeroBank Browser |
| xerofyt | xerophyte |
| xerografi | xerography |
| Xerox | Xerox |
| Xerxes | Xerxes |
| Xerxes I | Xerxes I of Persia |
| Xerxes II | Xerxes II of Persia |
| Xfce | Xfce |
| Xfera | Yoigo |
| XGA | XGA |
| XGL | Xgl |
| xhosa | Xhosa |
| XHTML | XHTML |
| Xi | Xi |
| Xi Wangmu | Queen Mother of the West |
| Xiadynastin | Xia Dynasty |
| Xiamen | Xiamen |
| Xiang | Xiang |
| Xibalba | Xibalba |
| Xichang Satellite Launch Center | Xichang Satellite Launch Center |
| Xie Xingfan | Xie Xingfang |
| Xindi | Xindi |
| Xingyi | Xingyiquan |
| Xinhairevolutionen | Xinhai Revolution |
| Xining | Xining |
| Xinjiang | Xinjiang |
| Xiongnu | Xiongnu |
| Xishuangbanna | Xishuangbanna Dai Autonomous Prefecture |
| Xiuhtlecutli | Xiuhtecuhtli |
| Xixia | Western Xia |
| Xkcd | Xkcd |
| XL Recordings | XL Recordings |
| XLR-kontakt | XLR connector |
| XMI | XML Metadata Interchange |
| XML | XML |
| XMMS | XMMS |
| XNOR | Logical equality |
| Xochimilco | Xochimilco |
| XOOPS | XOOPS |
| XQuery | XQuery |
| XScale | XScale |
| Xserve | Xserve |
| XSL | Extensible Stylesheet Language |
| XSLFO | XSL Formatting Objects |
| XSLT | XSL Transformations |
| Xuanzang | Xuanzang |
| XUL | XUL |
| Xuxa | Xuxa |
| XXX syndrom | Triple X syndrome |
| xylen | xylene |
| xylitol | xylitol |
| xylofon | xylophone |
