Rothschild's birdwing (Ornithoptera rothschildi) is a large birdwing butterfly, endemic to the Arfak Mountains in Western New Guinea.

This species was first recognized by entomologist Charles Edgar Pratt and described by George Kenrick in 1911.

It was named in honour of Lord Walter Rothschild who financed most of the expeditions of the naturalist Antwerp Edgar Pratt (1850-1924) and his two sons, Carl Brenders Pratt and Felix Biet Pratt, to British New Guinea from 1902 to 1903 and to the Arfak Mountains of Dutch New Guinea from 1909 to 1910.

The central patch is yellow with black tips abutting with smaller spots which are coloured lime green.

Its habitat are flowering meadows in an altitude of 2,000–2,700 metres (6,600–8,900 ft) above sea level.