| Acronym | Definition |
|---|
| VO | Very Old (cognac aged at least 4.5 years) |
| VO | Volume |
| VO | Voice Over (TV scriptwriting term) |
| VO | Virtual Organization |
| VO | Virtual Observatory |
| VO | Virtual Office |
| VO | Véhicule d'Occasion (French: Used Vehicle) |
| VO | Vor Ort (German: locally) |
| VO | Vecchio Ordinamento (Italian: Old Curriculum Requirements) |
| VO | Version Originale |
| VO | Very Optimistic |
| VO | Valve Opening |
| VO | Volatile Organic |
| VO | Observation Plane (US Navy) |
| VO | Velocity Obstacle (robotics) |
| VO | Shuttle Operations (US NASA) |
| VO | Visa Officer (various nations) |
| VO | Vegan Outreach |
| VO | ValueOptions |
| VO | Observation Squadron |
| VO | Vehicle Operations |
| VO | Voice Only |
| VO | Verbal Order |
| VO | Validation Office (US DoD) |
| VO | Victorian Order (British decoration for personal service to the sovereign) |
| VO | Variation Order |
| VO | Vertical Opening |
| VO | Directie Voortgezet Onderwijs (Dutch) |
| VO | Village Officers (India) |
| VO | Navy Battleship Observation Squadron (US Navy) |
| VO | Verifying Official |
| VO | Value Optimization |
| VO | Voluntary Opening |
| VO | Valence Orbital |
| VO | Verifying Officer |
| VO | Vendor Order |
| VO | Spotting Squadron (US Navy aviation unit designation used in 1922) |
| VO | Navy Observation Squadron (US Navy aviation unit designation used from 1920s to 1970s) |
| VO | Vision Operator |
| VO | Visitors and Observers |
| VO | Visual Opening (graphics) |
| VO | Votoms Online (gaming) |