The 2018–19 Plunket Shield was the 90th season of the Plunket Shield, the domestic first-class cricket competition in New Zealand. It took place between October 2018 and March 2019. Unlike the previous edition of the competition, the tournament featured eight rounds of matches, instead of ten. Central Districts were the defending champions. Up to eleven international players, including New Zealand's captain Kane Williamson, were available for the opening round of the tournament.