William Roy McGregor was a New Zealand zoologist and conservationist who was successful in halting forestry in the Waipoua forest and establishing the forest as a protected sanctuary.

Waipoua Forest is a forest, on the west coast of the Northland Region of New Zealand's North Island. It preserves some of the best examples of kauri forest remaining in New Zealand. It is notable for having two of the largest living kauri trees, Tāne Mahuta and Te Matua Ngahere.