What is the largest butterfly in the world?

The largest butterfly in the world is Queen Alexandra's birdwing. Its females can have wingspans slightly above 25 centimetres, making them larger than the males and larger than any other living butterfly species by wingspan.

This spectacular birdwing is found only in the forests of Oro Province in eastern Papua New Guinea. The species was described in 1907 by Lionel Walter Rothschild, who named it after Queen Alexandra, wife of Britain’s King Edward VII. Females are brown with pale markings, while the smaller males are vividly blue-green and black.

A common mix-up is confusing the largest butterfly with the butterfly that has the greatest wingspan in a particular measurement category, or with a visually larger-looking species such as the blue morpho. The Queen Alexandra's birdwing is also endangered and is listed in Appendix I of CITES, which makes commercial international trade highly restricted.