University students faced unexpected challenges in online learning during the Covid-19 pandemic. Findings from early phases of the Covid-19 pandemic and before show that online learning experiences may vary from student to student and depend on several personal characteristics. However, the relative importance of different students’ personal characteristics for their online learning experiences at later phases of the Covid-19 pandemic is still unclear. This cross-sectional, correlational study investigates how personal characteristics of university students are related to five dimensions of online learning perception and to their engagement and performance in online courses. In an online survey, 413 students from German universities provided full information on their online learning experiences and personal characteristics in terms of demographic information, Big Five personality traits, self-regulation skills, three facets of self-efficacy, and two types of state anxiety. Results of multiple regression analyses show that students’ age was significantly positively related to all online learning perceptions and engagement in online courses. Our findings also confirm that self-regulation skills and academic and digital media self-efficacy are important factors in various online learning experiences. In contrast, students’ personality traits and state anxiety were less important for most online learning experiences. Noteworthy, several bivariate associations between personal characteristics and online learning experiences are not reflected in the multiple regression model. This underscores the need to consider relevant variables simultaneously to evaluate their relative importance and to identify key personal characteristics. Overall, our results show valuable starting points for theory development and educational interventions.