HSD
- Hackett School District
- Hamstead railway station
- Hardanger Sunnhordlandske Dampskipsselskap
- Harrison School District (disambiguation)
- Hazelwood School District
- Heliophysics Science Division
- High School Diploma
- Hillsboro School District
- Historical Society of Delaware
- Hollywood Stunt Driver
- Homeland Security Department
- Hybrid Synergy Drive
- Hydroxysteroid dehydrogenase
- Hypermobility spectrum disorder
- Hypoactive sexual desire
- Tukey's honest significant difference