Introduction: Young workers are at risk of workplace injuries for numerous reasons. One contentious yet untested theory is that subjective invulnerability to danger—a sense of indestructability in the face of physical hazards—can affect some young workers’ reactions to workplace hazards. This study contends that subjective invulnerability can affect these reactions in two ways: (a) perceptions of physical hazards at work generate less fear of injury among those who perceive themselves as more invulnerable and/or; (b) fear of injury does not motivate speaking up about safety concerns (safety voice) among those who perceive themselves as more invulnerable. Method: This paper tests a moderated mediation model in which higher perceptions of physical hazards at work are related to higher safety voice intentions via higher fear of injury, but that subjective invulnerability reduces the extent to which: (a) perceptions of physical hazards at work are associated with fear of injury and/or; (b) fear of injury is associated with safety voice. This model is tested in two studies of young workers (Study 1 on-line experiment: N = 114, M age = 20.67, SD = 1.79; range = 18–24 years; Study 2 field study using three waves of data collected at monthly intervals: N = 80, M age = 17.13, SD = 1.08, range = 15–20 years). Results: Contrary to expectations, the results showed that young workers who feel more invulnerable to danger are more likely to speak up about safety when experiencing higher fear of injury, and that perceptions of physical hazards–safety voice relationship is mediated by fear of injury for those who perceive themselves to be more invulnerable to danger. Conclusions/Practical Applications: Rather than subjective invulnerability silencing safety voice as predicted, the current data suggest that subjective invulnerability may serve to accelerate how fear of injury motivates safety voice.