The purpose of this study was to determine the effects of dental hygienists’ grit, job satisfaction, and job commitment on dental hygiene job performance and the mediating effects of job satisfaction and job commitment on the relationship between grit. Methods: From May 25 to June 13, 2022, the researcher collected and analyzed data from 213 dental hygienists working at dental hospitals and clinics. For the data analysis, SPSS Statistics 21.0 was applied to conduct a t-test, one- way ANOVA, Pearson’s correlation analysis, and hierarchical regression analysis. Results: Grit was in charge of preventive work (scaling) (3.38±0.56, p<0.05), and the lower the stress (3.39±0.57, p<0.05), the higher the grit. Dental hygiene job performance was higher when they worked in Gwangju, Jeolla-do (3.88±0.50, p<0.01), and dental clinics (3.85±0.53, p<0.01). Job satisfaction (3.45±0.49, p<0.05) and job commitment (3.28±0.56, p<0.05) were high, as they had at least a bachelor’s degree. Less job stress was associated with higher job satisfaction (3.71±0.42, p<0.001) and job commitment (3.52±0.65, p<0.001). Job satisfaction and commitment had partial mediating effects on the relationship between dental hygienists’ grit and job performance. Conclusions: It is necessary to develop a program that helps improve grit in dental hygienists to strengthen their psychological resources, job satisfaction, and job commitment.