Developments in direct and indirect educational systems have increased the number of individuals with competencies that are higher than the required expectations of their current jobs. This concept of overqualification is drawing interest today, while underqualification was the focus in the past. Currently, research on perceived overqualification (POQ) has focused on its negative influences; however, this study aimed to explore the positive and nonlinear influence of POQ on job crafting and the moderating effect of career adaptability on these functions. Data were collected from 257 individuals in three Korean telecom companies. The results of hierarchical regression analysis indicate that POQ had a reverse U-shaped nonlinear influence on job crafting, indicating that an appropriate level of POQ can drive job crafting, leading to performance improvements in organizations and individuals. Moreover, career adaptability moderated the relationship between POQ and job crafting. When career adaptability was at an average or high level, the reverse U-shaped nonlinear influence of POQ on job crafting strengthened. These results are expected to assist in creating both an environment to reduce the negative influence of POQ and healthy sustainability in human resources development.