Cancer poses a significant and growing health challenge in Sub-Saharan Africa, contributing to increasing mortality rates. Access to radiotherapy, a critical component of effective cancer treatment, remains severely limited, thereby hindering progress towards achieving Sustainable Development Goal (SDG) 3, which aims to reduce premature mortality from non-communicable diseases, including cancer. This qualitative study explores the multifaceted challenges faced by patients in accessing radiotherapy services within Gauteng Province, South Africa, emphasising the urgent need for a comprehensive framework to improve access. Employing a cross-sectional qualitative design, in-depth interviews were conducted with 25 cancer patients undergoing radiotherapy to investigate the socio-economic and demographic barriers impacting their ability to access treatment. The study revealed significant barriers, including the limited availability of radiotherapy facilities, inefficient referral processes and substantial financial burdens. These challenges were often exacerbated by patients’ socio-economic status and geographic location, thereby highlighting disparities in access to care. Data from the other phases indicates long waiting times for consultations and treatment, and there are only two public radiotherapy facilities in the province, primarily concentrated in urban areas, with limited equipment and trained personnel to meet the growing demand. The findings underscore the pressing need for targeted interventions to enhance radiotherapy access in Gauteng Province, such as strategic investments in infrastructure, streamlining referral pathways and addressing financial constraints through targeted support programs. Addressing these challenges requires a multi-pronged approach involving government, healthcare providers and community organisations. Comprehensive strategies and increased investment are essential to improve access to radiotherapy in Sub-Saharan Africa, which is crucial for achieving SDG 3 and reducing cancer-related mortality. Without scaling up access, many lives will be unnecessarily lost to this treatable disease