To ensure the quality of the work done in the Korean career civil service system (which is characterized by stability, such as lifelong job security), the public sector must use methods to motivate their employees and improve their performance in the long run. In this study, we propose that grit, as a type of work motivation, can boost employee well-being (i.e., job satisfaction, job stress) and organizational outcomes (i.e., organizational commitment, performance). Therefore, the main objective of this study is to assess the validity of grit among public employees from a collectivist culture; to this end, we use the 2016 survey of Korean public officials ( N = 2,070). The results are as follows: (a) grit has a direct positive effect on quality of work life (QWL), (b) QWL can increase employee’s quality of life (QOL), and (c) professionalism and goal-oriented culture negatively and positively regulate grit and QWL. We also examined how employee motivation (e.g., grit) can enrich their QWL and QOL. Altogether, this study supports the argument that human resource (HR) managers should pay attention to grit. To achieve success, one needs not only some level of ability but also the zeal and capacity for hard labor, the latter two of which are considered to constitute grit. Given that, this research targeted grit in the Korean context—not the Western one—and examined its effects in the Korean public sector, where conscientiousness is emphasized.