This study measured the daytime sleepiness (DS) and work safety of fathers during the first 12 weeks of their babies’ lives (i.e., early fatherhood). A questionnaire was developed using the Epworth Sleepiness Scale (ESS), the Safety Behaviour at Work Scale, a self-reported sleep history, and a work-related incident history. Of the 221 participants, the vast majority reported they experienced less than 6 hours of interrupted sleep per night during the 12 weeks of the study, and an increasing frequency and severity of DS. The study also revealed an inverse correlation between ESS and Safety Behaviour at Work scores; fathers were 14% more likely to report a near-miss accident at work at 12 weeks. This study posits that antenatal classes and assessment of fathers’ sleepiness at work by occupational health practitioners could assist fathers in reducing daytime sleepiness and mitigating the risk of workplace incidents.