Heavy Work Investment (HWI), the extent to which individuals invest energy and effort into doing their work, has recently been studied in regards to job-related outcomes and work-life conflict. However, research is negligible on the influence HWI (i.e., workaholism and work engagement) may have on psychological well-being when an individual performs “meaningful” work. Specifically, the present study investigated the role of HWI in the relationships between work meaningfulness and the psychological well-being outcomes of perceived stress, life satisfaction, and the emotional exhaustion sub-dimension of burnout. The existing literature on work meaningfulness, the extent to which an individual considers their work to be valuable and worthwhile, provides positive implications for an individual’s well-being. Additionally, given that workaholism is considered “bad” and that work engagement is considered “good”, the aim of this study was to shed light on whether the presence of HWI moderated the relationship between work meaningfulness and psychological well-being. The sample contained 219 individuals who were either full time working professionals or part time working college students. Hayes’ PROCESS Command was used to test the moderation and mediation effects. Results indicated that workaholism and work engagement did not moderate the relationships of interest. However, work engagement did mediate these relationships. Implications, limitations, and avenues for future research are discussed.