The connection between grit and achievement in a variety of areas is well documented. Nevertheless, the factors that affect domain-specific academic grit and the relationship of these factors to academic achievement still require clarification. The present study aimed to explore the contribution of three main categories of variables: subjective well-being (SWB), coping resources (e.g., self-efficacy and help-seeking orientation (HSO)), and self-cultivation characteristics (e.g., savouring art and personal growth) to academic grit and academic achievement as well as the significance of academic grit as a predictor and mediator for academic achievement. The sample comprised a total of 351 university students between the ages of 18 and 58 from Anglophonic countries (US, Canada, and UK), and Israel. Using structural equation modelling (SEM), academic grit was found to be directly associated with academic achievement among university students while SWB, coping resources, and self-cultivation characteristics were only indirectly associated with academic achievement with the mediation of academic grit. These results have important educational implications since they reveal existing effects which should serve as a basis for the implementation of university programmes. The results indicate the importance of student well-being, coping resources, and self-cultivating characteristics, especially regarding personal growth to perform optimally at university studies.