Entrepreneurship education has been employed broadly in higher education, and one of the most popularly targeted outcomes is enhancing entrepreneurial mindset. However, the role of entrepreneurial mindset has not been examined in relation to career adaptability, which has been acknowledged as an important resource for adjustment, especially with the increased uncertainty caused by COVID-19. The current study investigated the relations among intolerance of uncertainty—specifically its sub-factors, prospective anxiety and inhibitory anxiety—career adaptability, and entrepreneurial mindset in 274 Korean college students facing school-to-work transition during COVID-19. The study conducted path analysis and evaluated the mediating effect of entrepreneurial mindset, using a 95% bootstrapping confidence interval, to better understand the role of entrepreneurial mindset in general career development in the context of uncertainty. The results found that inhibitory anxiety had an inverse association with career adaptability and entrepreneurial mindset, while prospective anxiety had a positive relation with career adaptability and entrepreneurial mindset. Entrepreneurial mindset and career adaptability showed a significantly positive relation, and the mediating role of entrepreneurial mindset between intolerance of uncertainty and career adaptability was also supported. Discussions on the role of entrepreneurial mindset are initiated and practical implications for entrepreneurship education are proposed along with the limitations of the study.