Fathers’ engagement in infant caregiving is linked with positive social, emotional, and developmental outcomes in children; however, its relationship with fathers’ own health is largely unknown. This longitudinal study examined associations between fathers’ caregiving engagement with their 6-month-old infants and their physical activity, sugar-sweetened beverage (SSB) consumption, nighttime sleep duration, and depressive symptoms 6 months later when infants were 12 months old. Participants were 143 fathers of infants (62.7% non-Hispanic White, 82.3% with a bachelor’s degree). Fathers reported their frequency of engagement in seven caregiving activities when infants were 6 months old. Fathers’ physical activity, SSB consumption, nighttime sleep duration, and depressive symptoms were assessed when infants were 6 and 12 months old. Multivariate logistic regression analysis was used to assess if fathers who reported higher infant caregiving at 6 months had more positive health outcomes at 12 months, controlling for fathers’ age, race/ethnicity, education, employment, household income, and the outcome at 6 months. Fathers who reported higher caregiving engagement when infants were 6 months old had increased odds of being sufficiently physically active 6 months later (unadjusted odds ratio [OR] = 1.19, 95% confidence interval [CI] = [1.00, 1.41]; adjusted OR = 1.47, 95% CI = [1.11, 1.96]). No links were identified between fathers’ caregiving engagement and their SSB consumption, nighttime sleep duration, or depressive symptoms. In summary, fathers’ engagement in infant caregiving may be beneficial to their physical activity in the first year after birth. There was insufficient evidence in this study that the benefits of caregiving engagement were experienced broadly across multiple health outcomes.