Due to the focus of studies about caregiving responsibilities on older caregivers, there has been a deficit of research on young caregivers. We aimed to investigate the association between caregiving and health/mortality risk in young caregivers when compared with their noncaregiving peers and older caregivers. A census-based record linkage was implemented, linking all residents enumerated in the 2011 Northern Ireland Census with subsequently registered deaths data, until the end of 2015. Among those aged 5–24 years at the 2011 Census, approximately 4.5% (19,621) of the cohort reported that they were caregivers. The presence of a chronic physical condition (such as mobility difficulties) and/or mental health condition was measured through the Census; all-cause mortality was assessed by official mortality records. Young caregivers were less likely than their noncaregiving peers to report chronic mobility problems (adjusted odds ratio (OR) = 0.84, 95% confidence interval (CI): 0.73, 0.96) but more likely to report chronic poor mental health (adjusted OR = 1.44, 95% CI: 1.31, 1.58). They also differed from older caregivers (P < 0.001) and were at significantly higher mortality risk than their peers (adjusted hazard ratio = 1.54, 95% CI: 1.10, 2.14). A dose-response relationship between hours devoted to caregiving duties and mortality risk was evident. We found that young caregivers were at significantly increased risk of poor health outcomes.