Through the lens of complexity, we present a nested case study describing a decolonisation approach developed and implemented by Waminda South Coast Women's Health and Welfare Aboriginal Corporation. Using Indigenous research methods, this case study has unfolded across three phases: 1) Yarning interviews with the workforce from four partner health services (n = 24); 2) Yarning circle bringing together key informants from yarning interviews to verify and refine emerging themes (n = 14); 3) Semi-structured interviews with a facilitator of Waminda's Decolonisation Workshop (n = 1) and participants (n = 10). Synthesis of data has been undertaken in stages through collaborative framework and thematic analysis. Three overarching themes and eight sub-themes emerged that centred on enhancing the capabilities of the workforce and strengthening interagency partnerships through a more meaningful connection and shared decolonisation agenda that centres Aboriginal and Torres Strait Islander families and communities. Health and social services are complex systems that function within the context of colonisation. Waminda’s innovative, model of interagency collaboration enhanced workforce capability through shared language and collective learning around colonisation, racism and Whiteness. This process generated individual, organisational and systemic decolonisation to disable power structures through trauma and violence informed approach to practice.