This study examined grit as a predictor of happiness in the first-time mothers and tested the mediating effects of the meaning of life (search for meaning and presence of meaning in life) and parental self-efficacy as the underlying mechanisms for the relationship between grit and first-time mothers’ happiness. Self-reported questionnaires were collected from 217 full-time mothers with infants and toddlers aged 0-2years. The results showed that (1) all variables in the research model were positively related, and (2) all single, double, and triple mediation effects were significant, with the exception of the search for meaning. This study showed that, despite the fact that the burden of caring for young children was the greatest for first-time mothers, grit increased mothers’ happiness by enhancing the meaning of life and sequentially equipped them with child-rearing efficacy. This work was significant as it was the first study to identify the positive workings of grit in the field of life, particularly for mothers who strived to fulfill their parenting role.