Orocrambus siriellus is a moth in the family Crambidae.

[2][3] This species is endemic to New Zealand,[4] where it has been recorded in Northland to Southland and on the Chatham Islands.

[5] It lives in habitat consisting of swampy areas.

Adults have been recorded on wing from December to February.

[5] The larval host plant of this species is currently unknown.