| Abbreviation | Definition |
|---|---|
| SEA | Sports Electronic Archiving |
| SEAFL | South Eastern Australian Football League |
| SEB | Straight Edge Bomber |
| SEC | Some Easy Conference |
| SEC | South Eastern Conference |
| SEC | Southeastern Conference |
| SEC | Speed Eliminates Competition |
| SEC | Standard Entry Class |
| SECA | Sports Event Capture Arrays |
| SECKS | SouthEastern Conference Kickoff Special |
| SEDA | Sports Education and Development Australia |
| SEG | Sports Entertainment Gear |
| SEIC | Safety Education and Instruction Council |
| SEL | Sport Einspritzer Lang |
| SEL | Swedish Esports League |
| SELA | Southeastern Louisiana University Lions |
| SEO | Sports Entertainment Organization |
| SEPT | Super Energized Physical Training |
| SERC | Scottish Endurance Riding Club |
| SERT | Self Erecting Rifle Target |