| HALO | Hallee Annabelle Little One 
| Others |
| HALO | Ham And Lettuce Ouch
| Others |
| HALO | Hari Assembly and Logistics
| Others |
| HALO | Harry Ainlay Learning Opportunity
| Others |
| HALO | Healing Attachment Loving Outreach
| Others |
| HALO | Health Achievement Learning Opportunities
| Others |
| HALO | Healthy Alternatives for Little Ones
| Others |
| HALO | Help and Lead Others
| Others |
| HALO | Helping And Leading Others
| Others |
| HALO | Helping Animals Live and Overcome
| Others |
| HALO | Helping Animals Live On
| Others |
| HALO | Helping Art Liberate Orphans
| Others |
| HALO | Hendrick Automotive Learning Online
| Others |
| HALO | Hexagon of Absolute Light and Organization
| Others |
| HALO | High Accuracy Location
| Others |
| HALO | High Achievement Learning Organization
| Others |
| HALO | High Altitude Logistics Orbital
| Others |
| HALO | High Altitude Long Operation
| Others |
| HALO | High Altitude Low Open
| Others |
| HALO | High Altitude Low Opening
| Others |
| HALO | High Angle Lift Off
| Others |
| HALO | High Automation Low Operating
| Others |
| HALO | High-Altitude Long Operation
| Others |
| HALO | High-Altitude Low-Opening
| Others |
| HALO | High-Altitude Low-Opening Parachute Technique
| Others |
| HALO | Hispanic American Leadership Organization
| Others |
| HALO | Home And Lot Owners
| Others |
| HALO | Homeless Assistance Leadership Organization
| Others |
| HALO | Hope And Life Outreach
| Others |
| HALO | Horizonal Application Layer Overlay
| Others |
| HALO | Hospital Affiliated Lobbyist Organization
| Others |
| HALO | Housing and Assisted Living Options
| Others |
| HALO | Houston Area Lighting Owners
| Others |
| HALO | Huge A** Large Ovoid
| Others |
| HALO | Husker Angels Loving Others
| Others |
| HALO | Hybrid Automotive Lightweight Optimization
| Others |
| HALO | Hypersonic Aircraft Launch Option
| Others |
| HALO | Hyundai Active Locking Operation
| Others |