The first formal description of the hook-billed kingfisher was by the French surgeon and naturalist René Lesson in 1827 under the binomial name Dacelo macrorrhina.

[2] The hook-billed kingfisher is now the only species placed within the genus Melidora which was introduced by Lesson in 1830.

The specific epithet macrorrhina is from the classical Greek makros for "long" and rhis for "nose".

The most common call is a long whistle followed by a series of higher pitched short notes.

It may dig into the soil searching for prey in a similar manner to the shovel-billed kookaburra.