Recent genetic evidence on MacGregor's honeyeater confirms that it belongs to the family Meliphagidae.

The name commemorates its discoverer, the administrator of British New Guinea, Sir William MacGregor.

Sir William's surname was originally, and thus formally, McGregor but he adopted the spelling MacGregor while in New Guinea as his personal preference.

[3] Due to a small and declining population, MacGregor's honeyeater is evaluated as vulnerable on the IUCN Red List of Threatened Species.

The nest is a bulky cup of moss, lichen and sticks, lined with small leaves and stems.