The objective of this article is twofold – (i) to identify the incidence of education-job mismatch among the young workers in Malaysia across several socio-economic factors and (ii) to investigate the factors that would explain the incidence of education-job mismatch among young workers. The analysis of this article utilises the first nationally representative study of the School-to-Work Transition of Young Malaysians (SWTS) survey conducted in 2018. The Job-Analyst method is applied to answer the first objective. Results indicated that the incidence of education-job mismatch was evident among the young workers, with almost half of the sample respondents being under and overeducated in their employment. A higher mismatch is evident within the field of study, employment sector, and income range. Approximately half of the respondents considered their field of study slightly relevant or irrelevant to their current jobs, indicating a serious mismatch among the respondents. Based on the analysis using multinomial logistic regression, the socio-educational background of young workers was found to contribute to the determinants of education-job mismatch significantly. The likelihood of overeducation was strongly associated with young workers’ reservation wage, gender, education qualification, several fields of study, employment status, and employment sectors. This article contributes to the literature on young workers in the Malaysian context, which has not been previously explored.