This paper explores the process of co-designing a mātauranga-Māori-informed mindfulness intervention with rangatahi in a wharekura and examines the effects on wellbeing. Mahitahi co-design methodology underpinned the design, implementation and evaluation of the intervention, and quantitative psychological tests measured improvements in wellbeing and dispositional mindfulness. Findings showed positive indications for a decrease in levels of psychological distress, improvements in Māori quality of life domains and higher levels of dispositional mindfulness. The effective mātauranga-Māori-informed wellbeing components of the intervention were he āhuru mōwai, mahi a ngā tīpuna, ngā kaitiaki, te taiao, whanaungatanga and hohou te rongo. Future application of the intervention in mainstream schools and communities is needed to assess the efficacy of the intervention for rangatahi in other environments, the sustainability of mindfulness practice for rangatahi and the long-term effects on wellbeing.