The King bird-of-paradise prefers to reside in lowland rainforests, gallery forests, and forest edges, as well as tall secondary forests that have been disturbed.

The King bird-of-paradise is a frugivore and its diet primarily consists of fruits and arthropods.

The mating behavior of King birds-of-paradise involves the males attracting multiple females. To do so, they exhibit an elaborate display that includes perching upright on a branch, vibrating their wings, spreading their feathers, and hanging upside down from the branch while swinging like a pendulum. Once a female is attracted, she will build an open cup-shaped nest within a tree cavity and lay up to two eggs. Incubation lasts up to 17 days, after which the female will care for the chicks until they are fully grown.

The King bird-of-paradise, as stated by the IUCN, can be found commonly and extensively across its habitat, but there is no specific count on the total population. Presently, this bird is categorized as being of Least Concern (LC) by the IUCN Red List, and its population appears to be holding steady.