Orocrambus lewisi is a moth in the Crambidae family. It was described by Gaskin in 1975. It is found in New Zealand, where it has been recorded from the South Island, Stephens Island and the south-west tip of the North Island. The wingspan is 28–30 mm. The forewings are yellow brown with a white median streak, bordered by dark brown. The hindwings are shining brownish white. Adults have been recorded from October to March. The larvae feed on Poa caespitosa.