HSD may stand for:
- Hybrid Synergy Drive - a set of hybrid car technologies developed by Toyota
- Homeland Security Department
- Hamstead railway station, England; National Rail station code HSD.
- Hardanger Sunnhordlandske Dampskipsselskap, a Norwegian transport company.
- High Speed Data
- High speed digital - the data rate regime in which signal integrity, power integrity, and EMI/EMC issues must be considered for successful transmission
- High speed diesel fuel, for diesel engines
- Historical Society of Delaware
- Hollywood Stunt Driver, a live show at Warner Bros. Movie World.
- Hypertonic Saline-Dextran, an intravenous liquid administered in emergency resuscitation from hypovolemic shock.
- Hypoactive Sexual Desire, refers to a low level of sexual desire.
- Heliophysics Science Division, a branch of NASA, the American space agency, which explores the solar atmosphere and its interactions with earth.
- Hydroxysteroid dehydrogenase
- Tukey honestly significant difference test, a multiple comparisons method in statistics