| Acronym | Definition |
|---|
| EO | Executive Order |
| EO | Equal Opportunity |
| EO | Essential Oil |
| EO | Earth Observation |
| EO | Exempt Organizations (accounting) |
| EO | Executive Officer |
| EO | Esperanto (ISO Language Code) |
| EO | Ethylene Oxide |
| EO | Earth Observing |
| EO | Every Other |
| EO | Electro-Optic(al) |
| EO | English Only (education) |
| EO | Evangelische Omroep (Dutch TV and radio) |
| EO | Engine Oil |
| EO | Event Organizer |
| EO | Explosive Ordnance |
| EO | Education Outreach (various organizations) |
| EO | Education Otherwise (UK) |
| EO | Ex Officio (Latin: By Virtue of Office) |
| EO | Exchange Online (Microsoft Office) |
| EO | Earth Orbit |
| EO | Exterior Orientation |
| EO | Extremal Optimization (statistical physics) |
| EO | Eve Online (game) |
| EO | Equipment Operator (Navy Seabee rating) |
| EO | Eastern Orthodox (religious denomination) |
| EO | Enforcement Officer |
| EO | Erasable Optical |
| EO | End Office |
| EO | Edmonton Oilers (hockey) |
| EO | Empowered Official (various organizations) |
| EO | Escrow Officer |
| EO | Emergency Operation |
| EO | Endless Online (computer game) |
| EO | Ethics Officer |
| EO | Entrepreneurial Orientation (corporate traits) |
| EO | Employers Organisation (UK government) |
| EO | Employee Organization |
| EO | Early Out |
| EO | Electrolyzed Oxidizing |
| EO | Engineering Order |
| EO | Establishing Operation (applied behavior analysis) |
| EO | Emeka Okafor (basketball player) |
| EO | Encarta Online (Microsoft) |
| EO | Execute Order |
| EO | Electoral Office |
| EO | Equality Officer |
| EO | Engagement Operations |
| EO | Epilepsy Ontario (Thornhill, ON, Canada) |
| EO | Event Order (hospitality industry) |
| EO | Elliot and Olivia (Law & Order: Special Victims Unit; TV show) |
| EO | Enabling Objective |
| EO | Emergency Override |
| EO | Extra Over (construction industry) |
| EO | Edmonton Online (.net) |
| EO | Special Delivery Official (Scott Catalogue prefix; philately) |
| EO | Electrical Operator (US Navy submarine watchstation) |
| EO | Evolved Online (message board) |
| EO | Elita One (Transformers character) |
| EO | Earth Escape Orbit |
| EO | Elderly-Onset |
| EO | (USN Rating) Equipment Operator |
| EO | Euclid Orchestra (Euclid, OH) |
| EO | Engage Order |
| EO | Engine/Engineering Officer (Navy) |