Hepatitis C (HCV) is highly prevalent among people who are incarcerated. HCV treatment-as-prevention was implemented in the SToP-C trial in four correctional centres in New South Wales , Australia to determine whether prison-wide scale up of antiviral treatment was an effective strategy to reduce HCV incidence and prevalence in the prison setting. A qualitative assessment was undertaken with prison-based correctional and health personnel at each of the four prisons to understand operational, sociological, and cultural barriers and enablers to scale up. Informed by a framework for scaling up population health interventions, this analysis examines recommendations by correctional and justice health personnel for HCV treatment-as-prevention scale up in the prison setting. Correctional (n=24) and justice health (n=17) personnel, including officers, nurses, and senior administrators, participated in interviews across the four prisons where SToP-C was delivered and included two maximum security, one minimum security, and one women's medium/minimum security prisons. Scaling up HCV treatment-as-prevention was contingent on compatibility (including sentence length), efficacy (securely funded positions for dedicated personnel and continuity of care for patients transferring between prisons), stakeholder analysis (generally the whole of prison workforce, particularly custodial officers and senior administrators), reach (reliant on peer and officer champions), and legitimised change (via dedicated officers who could instigate cultural shifts). Achieving scale up of such an intervention should be guided by an understanding of the potential barriers and enablers. This analysis showed key considerations for HCV treatment-as-prevention scale up in correctional centres.