Knee osteoarthritis causes considerable pain, disability and reduced quality of life, disproportionately impacting Māori. Rapidly increasing prevalence, costs and demands for joint replacement will overwhelm the health system unless major system change occurs. Community-based interventions are known to substantially reduce osteoarthritis impact and cost. Community pharmacists are underused yet trusted providers of health information and services who could improve people’s osteoarthritis knowledge and self-management abilities and coordinate effective care and support. The Care for Osteoarthritis through Pharmacy Education and Referral (COPER) intervention allows knee osteoarthritis to be identified in community pharmacies, provides evidence-based information and resources, and links people with effective, accessible, funded interprofessional care that meets health needs, goals, and preferences. It is rapidly scalable and implementable using existing community healthcare providers. We will test whether COPER reduces pain, impairment, and costs. We will recruit equal numbers of Māori and non-Māori participants to ensure that COPER advances Māori health.