Encyclopedias, Almanacs, Transcripts, and Maps
- Horse-Whispering
- Horsehair Worms
- Horsehair Worms
- Horseman's Word
- Horses, Zebras, and Asses: Equidae
- Horseshoe Bats: Rhinolophidae
- Horseshoe Crabs
- Horseshoe Crabs
- Horseshoe Crabs: Merostomata
- Horseshoes
- Horsetails
- Horsetails
- Hospital, Contemporary Ethical Problems of the
- Hospital, Medieval and Renaissance History of the
- Hospital, Modern History of the
- Hospitals and Treatment Facilities in the Ancient World
- Hot Cross Buns
- Hotspots
- Houghton, Georgina (d. 1887)
- Houghton, Michael (d. ca. 1956)