The 1918 New Zealand rugby league season was the 11th season of rugby league that had been played in New Zealand.
See also: List of New Zealand Kiwis matches. New Zealand played no international matches in 1918.
Auckland again held the Northern Union Cup at the end of the season.
See also: Auckland Rugby League club trophies. Ponsonby won the Auckland Rugby League's competition.[1] City won the Roope Rooster.
Ponsonby then traveled to Canterbury and won the Thacker Shield from Sydenham, winning 11–0.[2] Ponsonby included Sam Lowrie, Thomas McClymont and Bill Walsh.[3]
Railway XIII had merged with Grafton Athletic at the start of the year. Karl Ifwersen played for Grafton.[3]
Sydenham won the Canterbury Rugby League's competition, for which they were awarded the Thacker Shield.[1]
Avon and Woolston joined the Canterbury Rugby League during the season.[2]
The Wellington Rugby League's competition was suspended from 1916 until 1918.