This article considers how becoming a father affects men’s employment levels and tests whether the effects of fatherhood differ by the relationship of the father to the child’s mother at the time of the birth. We use data from the Fragile Families and Child Wellbeing Study to fit growth curve models of new fathers’ employment trajectories for the first five years after they become fathers. Prior to becoming a father, married men worked more hours per week and more weeks per year than cohabiting and nonresident fathers. By five years after the birth, differences in employment between unmarried and married fathers had diminished. The transition to fatherhood is associated with an increase in employment for unmarried fathers but is not associated with significant changes in employment for married fathers.