This study was conducted to explain social relation based on psycho-social climate, psychological wellbeing components, and emotional intelligence among undergraduates of Olabisi Onabanjo University, Ogun State, Nigeria. The statistical population consisted of all undergraduates of Olabisi Onabanjo University. Participants were randomly selected with a multi-stage method. Finally a total of two thousand (2000) respondents participated in the study. The selection cut across all various levels in each faculty. The age range of the respondents is between 16-27 years with mean age of 21.37 and standard deviation of 8.33. The respondents consist of 1021 (52.4%) males and 926 (47.6%) females. Four validated instruments were used for data collection. The multiple regression method and correlation coefficient was used to analysis data. The result has established that psychological wellbeing (control of self and events, happiness, social involvement, self-esteem, mental balance, sociability), emotional intelligence and psychosocial climate were significant in explaining undergraduates' social relation. Also, It was found out that 18.6% of the total variance in students' social relation is accounted for by the combination of psychological wellbeing components, emotional intelligence and psychosocial climate of the university. This study concluded that when individual's sense about connection with a positive social context is "ideal", he or she is more likely to exhibit appropriate social behaviours.