| Hyacinthus | Hyacinthus |
| Hyaena hyaena | Hyaena hyaena |
| Hyaenidae | Hyaenidae |
| Hyaenodon | Hyaenodon |
| Hyde Park | Hyde Park |
| Hyderabad | Hyderabad |
| Hydra | Idra |
| Hydra viridis | Chlorohydra viridissima |
| Hydrangea | Hydrangea |
| Hydro-Man | Hydro-Man |
| Hydrochoerus hydrochaeris | Hydrochoerus hydrochaeris |
| Hydrodamalis gigas | Hydrodamalis gigas |
| Hydrophyllaceae | Hydrophyllaceae |
| Hydropotes inermis | Hydropotes inermis |
| Hydrozoa | Hydrozoa |
| Hydrurga leptonyx | Hydrurga leptonyx |
| Hydrus | Idra Maschio |
| Hyla | Hyla |
| Hyla arborea | Hyla arborea |
| Hylaeosaurus | Hylaeosaurus armatus |
| Hylidae | Hyla |
| Hylobates | Hylobatidae |
| Hylobates lar | Hylobates lar |
| Hylobatidae | Hylobatidae |
| Hylocereus | Hylocereus |
| Hylochoerus meinertzhageni | Hylochoerus meinertzhageni |
| Hyman Rickover | Hyman Rickover |
| Hymenocallis | Hymenocallis |
| Hymenomycetes | Basidiomycetes |
| Hymenoptera | Hymenoptera |
| Hymne Monégasque | Inno monegasco |
| Hymni i Flamurit | Hymni i Flamurit |
| Hyoscyamus niger | Hyoscyamus niger |
| Hypacrosaurus | Hypacrosaurus |
| Hypericaceae | Hypericum |
| Hypericum | Hypericum |
| Hypericum perforatum | Hypericum perforatum |
| Hyperoodon | Hyperoodon ampullatus |
| Hypertext Transfer Protocol | HTTP |
| HyperThreading | Hyper-Threading |
| HyperTransport | HyperTransport |
| Hypervisor | Hypervisor |
| Hypospadias | Ipospadia |
| Hypsilophodon | Hypsilophodon foxii |
| Hyracoidea | Hyracoidea |
| Hyracotherium | Hyracotherium |
| Hyrule | Hyrule |
| Hyrulian | Hyrule |
| Hyssopus officinalis | Hyssopus officinalis |
| Hystricidae | Hystrix cristata |
| Hystrix | Hystrix cristata |
| Hystrix cristata | Hystrix cristata |
