In many countries, university students experience various stressors that may negatively affect their psychological well-being (PWB). Hence, they are at risk for physical and mental problems. This research aimed to examine the predicting effects of mindfulness, self-efficacy, and social support on psychological well-being among undergraduate students. A non-experimental research was conducted at a university in the Philippines. Power analysis was used to calculate an adequate sample size and a convenience sampling of 630 was recruited. Data were collected through online self-reported questionnaires from year 2013 to 2015. Descriptive statistics, correlational analyses, and structural equation modelling were performed to analyse the research data. Results showed that the participants were mostly Filipino, female, Christian, and in Schools of Nursing and Medicine. Mindfulness, self-efficacy, support from family, support from friends, and support from significant others were significant predictors of psychological well-being. Mindfulness was the strongest predictor of positive psychological well-being whereas self-efficacy was the strongest predictor of negative PWB. Psychosocial interventions, with the focus on strengthening mindfulness and self-efficacy, could be delivered to students to help enhance psychological well-being among undergraduate students. More studies can be undertaken to test the interventions and multi-centred research can be conducted to enhance generalisability of research findings.