Objective: This study examines the influence of nonstandard employment and unemployment on delayed marriage among individuals in Japan by categorizing marriage formation into premarital partnerships entry and marriage entry from premarital partnerships stages. Background: Employment uncertainty is linked to the postponement of union formation as well as to an increase in cohabitation in place of marriage. However, the postponement of marriage has also occurred in countries without being accompanied by an expansion in cohabitation, suggesting that employment uncertainty may hinder the former stages of union formation–premarital partnership–in these countries. Method: Using nationally representative panel survey data from Japan covering the period of 2007–2021 and targeting young- and middle-aged individuals, binary logit models were employed to predict entry into premarital partnership and into marriage from such partnerships. Results: The influence of nonstandard employment and unemployment varies between premarital partnership formation and marriage formation from premarital partnership. Nonstandard employment and unemployment are significantly associated with premarital formation for both men and women, which is not observed after controlling for income. The association of employment with marriage formation from partnership is more evident among men than among women. Conclusion: The influence of employment uncertainty is apparent even in the formation of a premarital partnership. This study extends previous arguments on delayed union formation and employment uncertainty into the premarital partnership phases, which entail searching for and evaluating a potential marital partner.