Background <p>The COVID-19 pandemic significantly disrupted substance use services, potentially exacerbating existing inequities in access to treatment. This study examines the perspectives of senior managers and decision-makers in Wales regarding equity issues in substance use services during the pandemic.</p> Methods <p>Semi-structured interviews were conducted with fifteen senior managers and decision-makers from various organisations in the substance use field in Wales. Interviews were conducted during autumn 2020. Data were analysed using reflexive thematic analysis to identify key themes related to equity in access to treatment.</p> Results <p>Key findings highlighted significant disparities between third sector and statutory NHS services, particularly in access to PPE, and recognition as essential workers. The rapid shift to digital service provision exposed a digital divide, potentially excluding vulnerable service users. However, the pandemic also accelerated innovations in service delivery, such as the introduction of long-acting injectable buprenorphine and revised take-home medication policies. Long-term concerns included the economic impact on vulnerable populations, potential increases in mental health issues and substance use, and funding uncertainties for third sector services.</p> Conclusions <p>The pandemic exposed and exacerbated existing inequities in substance use services while also driving rapid innovation. Findings suggest a need for greater recognition and support for third sector services, strategies to address the digital divide, and sustained funding to ensure equitable access to treatment. These insights can inform policy and practice to develop more equitable and resilient substance use services in preparation for any future crises.</p>