The giant hummingbird is the only member of the genus Patagona and the largest member of the hummingbird family, weighing 18–24 g (0.63–0.85 oz) and having a wingspan of approximately 21.5 cm (8.5 in) and length of 23 cm (9.1 in). This is approximately the same length as a European starling or a northern cardinal, though the giant hummingbird is considerably lighter because it has a slender build and long bill, making the body a smaller proportion of the total length. This weight is almost twice that of the next heaviest hummingbird species and ten times that of the smallest, the bee hummingbird.

Hummingbirds are birds native to the Americas and comprise the biological family Trochilidae. With approximately 366 species and 113 genera, they occur from Alaska to Tierra del Fuego, but most species are found in Central and South America. As of 2024, 21 hummingbird species are listed as endangered or critically endangered, with numerous species declining in population.