The New Zealand Ministry for Culture and Heritage gives a translation of "long night" for Pōnui.

[2] The island is the site of some of the earliest archaeological remains of early Māori in the Auckland region, dating to at least the 1400s.

[4][5] The island now consists of three farms, two owned by the Chamberlin family and one by John Spencer.

From the 1880s until the early 20th century, stone and sand from the island was extracted for use in concrete structures in Auckland.

[6] The island is a popular site for youth camps for organisations such as Scouts.