| VectorLinux | — | — | — |
| VenenuX | — | — | — |
| Venix | IntervalZero | 1983 | — |
| Versados | Motorola | — | — |
| Versatile Real-Time Executive | Jim Ready | — | — |
| Version 10 Unix | — | — | — |
| Version 6 Unix | Bell Labs | 1975 | 4-clause BSD License, proprietary license |
| Version 7 Unix | — | — | 4-clause BSD License |
| Version 8 Unix | — | — | — |
| Version 9 Unix | — | — | — |
| Verve | Microsoft Research | — | — |
| VibeOS | — | 2025 | MIT License |
| Vibrante | Nvidia | — | — |
| VIDAA | Hisense | — | — |
| Vietlinux | — | — | — |
| Vine Linux | — | — | — |
| Viperr | — | — | — |
| VirtuOS | — | — | — |
| Visi On | VisiCorp | — | — |
| VisionOS | Apple Inc. | — | — |
| VisionOS 2 | Apple Inc. | — | — |
| VisionOS 26 | — | — | — |
| VisionOS 27 | — | — | — |
| Visopsys | — | — | GNU General Public License, version 2.0 |
| Vitalinux | — | — | — |
| VLOS | — | — | — |
| VM | IBM | — | — |
| VM-CP | IBM | — | — |
| VMware ESXi | VMware | — | — |
| Void Linux | — | 2008 | BSD licenses, free software, ISC license |
| Volumio (music player) | — | — | open-source software, GNU General Public License |
| VortexBox | — | — | — |
| VOS3 | Hitachi | — | — |
| VP/CSS | IBM, National CSS | — | — |
| VPS/VM | Boston University | — | — |
| VS/9 | UNIVAC | — | — |
| VSE | IBM | — | — |
| VSTa | — | — | GNU General Public License |
| Vw.os | Volkswagen Group | — | — |
| VxWorks | Wind River Systems | — | end-user license agreement |
| Vyatta | Brocade Communications Systems | — | GNU General Public License |
| VyOS | — | — | GNU General Public License, version 2.0 |
| WAITS | Stanford Artificial Intelligence Laboratory | — | — |
| Wando OS | — | — | — |
| Wang VSOS | Wang Laboratories | — | — |
| WatchOS | Apple Inc. | — | — |
| WatchOS 1 | Apple Inc. | 2015 | Apple Public Source License |
| WatchOS 10 | Apple Inc. | — | — |