Research concerning rational emotive behaviour therapy (REBT) and autonomous and controlled motivation within athletic settings is burgeoning. It is proposed that irrational beliefs (i.e., illogical, rigid, and extreme) together with controlled forms of motivation, can determine psychological well-being and physical health in these contexts. For example, research indicates that extreme negative self-evaluation (i.e., self-depreciation) is related to more controlled (less autonomous) motivation regulation, which may underpin poorer health. Though, research is yet to understand the concomitant influence of both irrational beliefs and motivation regulation on work related variables such as presenteeism, persistence and turnover intention, as well as non-work-related variables such as life satisfaction and mental-wellbeing. The present two study paper examines the latent profile structure of irrational beliefs and motivation regulation, and how these latent profiles relate to health and work-related variables. Across studies 1 and 2, results indicated a two-class profile whereby class 1 is characterised by low irrational beliefs and high self-determined motivation (low irrational engagement), and class 2 is characterised by high irrational beliefs and low self-determined motivation (high irrational engagement). Those in Class 2 reported poorer life satisfaction, persistence, and presenteeism, as well as greater depression, anxiety, stress, intention to quit, and absenteeism than those in class 1. Thus, findings indicate that poorer work and health outcomes are associated with greater irrational work engagement. The findings are discussed in relation to the practical implications for occupational workers.