Background Lebanese adults face daily obstacles due to their numerous responsibilities and non-ending external pressures to the extent that Lebanon has been ranked second among highest negative experiences countries worldwide. A sparse number of international studies showed that positive social support, religiosity and cognitive reappraisal would decrease psychological distress, but none in Lebanon. This study aimed to evaluate the association between social support, religiosity and psychological distress among Lebanese adults, taking into consideration the moderating role of emotion regulation. Methods 387 adult participants enrolled in this cross-sectional study between May and July 2022. Participants were chosen from five different governorates in Lebanon, using the snowball sampling technique, and were asked to complete a structured questionnaire, which included the following scales: the Mature Religiosity Scale, the Emotional Regulation Scale, the Depression Anxiety Stress Scale, and the Multidimensional Scale of Perceived Social Support. Results The interaction social support by cognitive reappraisal was significantly associated with psychological distress; at high levels of cognitive reappraisal and low levels of expressive suppression, higher social support (Beta = − 0.07; p = .007) was significantly associated with lower psychological distress. The same was found at high levels of cognitive reappraisal and moderate levels of expressive suppression (Beta = − 0.08; p = .021). Social support alone was not significantly associated with psychological distress in the model (Beta = 0.15; t = 1.04; p = .300; 95% CI − 0.14; 0.44). Conclusion This cross-sectional study has provided evidence that the adequate use of emotional regulation skills such as high level of cognitive reappraisal and low level of expressive suppression with presence of social support would remarkably decrease psychological distress. This result casts a new light on clinical approaches to tackle this association between the emotional regulation of a patient in interpersonal psychotherapy.