[3] In 1743 the English naturalist George Edwards included an illustration and a description of the Antillean crested hummingbird in his A Natural History of Uncommon Birds.

[5] The Antillean crested hummingbird is now the only species placed in the genus Orthorhyncus that was introduced in 1799 by Bernard Germain de Lacépède.

It demonstrates the general sexual dimorphism for hummingbirds where the male is bright and colorful whilst the female is more tannish and dull.

The subspecies can be distinguished by the colour of their crests: exilis is wholly green or slightly tinged blue on tip; ornatus has the terminal portion abruptly blue; cristatus is golden to emerald, violet terminally; emigrans is similar to the nominate but more bluish violet, throat paler grey; the degree of paleness in underparts of female varies with race.

The nest interior is lined with soft plant fibre and the outside decorated with pieces of dead leaves, lichens, moss or bark.

Clutch size is of two white eggs, size 11·6 mm × 8–8·2 mm;[18] incubation is 17–19 days done by the female who will also persistently attack intruders;[19] chicks are a darkish grey with two dorsal rows of down;[20] fledging period is about 19–21 days; young remain with female for 3–4 weeks; single brood.

Antillean Crested Hummingbird feed from near the ground and up to the canopy of tall trees but appear to prefer flowering plants of the understory.