The integration of mental health (MH) services into tuberculosis (TB) and HIV care remains a significant challenge in South Africa’s Free State province. This study seeks to understand the perspectives of public health programme managers on the barriers to such integration and to identify potential strategies to overcome these challenges. Data were collected between February and October 2021 using qualitative methods including four individual semi-structured interviews and two focus group discussions with a total of 15 managers responsible for the MH, primary healthcare, TB, and HIV programmes. Thematic data analysis was guided by an adapted version of the World Health Organization’s “building blocks” framework encompassing “service delivery”, “workforce”, “health information”, “essential medicines”, “financing”, and “leadership/governance”. Additionally, the analysis underscored the crucial role of “people”, acknowledging their significant contributions as both caregivers and recipients of care. Managers highlighted significant concerns regarding the insufficient integration of MH services, identifying structural barriers such as inadequate MH management structures and staff training, as well as social barriers, notably stigma and a lack of family treatment adherence support. Conversely, they recognised strong management structures, integrated screening, and social interventions, including family involvement, as key facilitators of successful MH integration. The findings emphasise the need for a whole-system approach that addresses all building blocks while prioritising the role of “people” in overcoming challenges with integrating MH services into TB and HIV care.