Purpose <p>Professionals providing substance use treatment services often report poor workplace well-being. Moreover, professionals’ beliefs about addiction may influence their view of clients, treatment delivery and their well-being at work. Most research has been undertaken in Western countries, hence this study investigated workplace well-being and addiction beliefs of substance use (SU) professionals in Singapore.</p> Methods <p>A mixed-methods design was employed. Fifteen participants completed questionnaires related to their well-being at work and addiction beliefs, before participating in a semi-structured interview.</p> Results <p>Descriptive analyses revealed that most participants experienced a moderate level of satisfaction with their work and moderate burnout. Reflexive thematic analysis generated four themes: (1) deriving and maintaining meaningfulness; (2) clarity of role and support for effective performance; (3) holding a multidimensional and nuanced view of addiction promotes satisfaction and motivation; and (4) navigating systemic challenges. Workplace well-being was negatively impacted by perceptions of organisational and systemic challenges.</p> Conclusions <p>SU professionals derived satisfaction and stayed motivated by crafting their work to re-align with their personal values and beliefs, finding role-clarity, adopting a multidimensional and flexible model of addiction and having external support. Implications highlight the role that organisational training, supervision and career development can play in supporting SU professionals.</p>