Is the belief in a just world among students also stable under COVID-19? To answer this question, a study was conducted with university students from Germany (n = 291). The aim of the study was to analyze the predictive performance of the personal belief in a just world (PBJW) on students' life satisfaction and academic cheating and to take into account important mediators from the university context such as fellow student justice, lecturer justice, and procrastination. Derived from existing research, university students with a stronger PBJW should be more satisfied with their lives and cheat less than those with a weaker PBJW. The results support the hypothesized direct effects of PBJW on life satisfaction. Procrastination additionally mediated the effect of PBJW on life satisfaction. The level of PBJW predicted academic cheating only indirectly. The mediators procrastination and lecturer justice were crucial here. The results persisted when gender, learning, time to exam, socially desirable responding, general BJW, and self-efficacy were controlled. The findings were discussed in relation to the stressful situation caused by COVID-19. A reflection on the adaptive function of PBJW as a resource and relevant situation-specific mediators for university research and practice followed.