What is the largest venomous snake by length?

The king cobra is the largest venomous snake by length. Adults commonly reach around 3 to 4 metres, and exceptional individuals can grow beyond 5 metres. Its scientific name is Ophiophagus hannah, meaning “snake-eater,” a reference to its specialized diet, which includes other snakes.

The king cobra lives across parts of the Indian subcontinent, Southeast Asia, southern China, and nearby regions. It is not technically a true cobra in the genus Naja; it belongs to its own genus, Ophiophagus. When threatened, it can raise the front portion of its body, spread a hood, and produce a deep warning growl.

The key distinction is length rather than venom potency. The inland taipan has more toxic venom by commonly cited LD50 comparisons, but it is much shorter. Reticulated pythons and green anacondas can exceed king cobras in length, yet they are constrictors rather than venomous snakes. The king cobra is therefore the standard answer when the question specifies the longest venomous snake.