Background: Primary healthcare services have principal responsibility for providing child and youth wellbeing and mental health services, but have lacked appropriate measurement instruments to assess the wellbeing of Indigenous children and youth or to evaluate the effectiveness of programs and services designed to meet their needs. This review assesses the availability and characteristics of measurement instruments that have been applied in primary healthcare services in Canada, Australia, New Zealand and the United States (CANZUS countries) to assess the wellbeing of Indigenous children and youth. Methods: Fifteen databases and 12 websites were searched in December 2017 and again in October 2021. Pre-defined search terms pertained to Indigenous children and youth, CANZUS country names, and wellbeing or mental health measures. PRISMA guidelines were followed, with eligibility criteria guiding screening of titles and abstracts, and selected full-text papers. Results are presented based on the characteristics of documented measurement instruments assessed according to five desirability criteria: development for Indigenous youth populations, adherence to relational strength-based constructs, administration by child and or youth self-report, reliability and validity, and usefulness for identifying wellbeing or risk levels. Results: Twenty-one publications were found that described the development and or use by primary healthcare services of 14 measurement instruments, employed across 30 applications. Four of the 14 measurement instruments were developed specifically for Indigenous youth populations, four focused solely on strength-based wellbeing concepts but none included all Indigenous wellbeing domains. Conclusion: There is a diversity of measurement instruments available, but few fit our desirability criteria. Although it is possible that we missed relevant papers and reports, this review clearly supports the need for further research to develop, refine or adapt instruments cross-culturally to measure the wellbeing of Indigenous children and youth.