BACKGROUND: Pre-marital sex is a sexual interest practiced by people who are yet to get married and has ended up being accepted specifically in western countries. Sex before marriage is sexual behavior engaged in by single people. In the past, having sex before getting married is seen as a moral dilemma that many cultures forbade and that many people regarded to be sin in many religions, although it has gained wider acceptance across the board. OBJECTIVES: This study was carried out to determine the perception, practices, and factors associated with pre-marital sex, courtship, and its influences among Osun State University Undergraduates, Osogbo, Osun State. METHODOLOGY: The study was a descriptive study, and respondents were selected using multi-stage sampling technique. Students of Osun State University, Osogbo main campus form the population of the study and its sample size was calculated using Leslie Kish’s formula. A total of 387 responses were validated from the survey. The instrument for data collection was a self-administered semi-structured questionnaire consisting of four sections. The data obtained were collated, examined for completion, coded, imputed, and analyzed using SPSS v21. RESULTS: The mean age of the respondents was between 19.19±2.17, and the majority were between 18 – 24 years. About 52% of the respondents show a positive perception of premarital sex and courtship. Also, in the practice of courtship majority (88.3%) of the respondents think those that go around together are courting and from the responses obtained and analyzed from the factors leading to pre-marital sex, the findings revealed that peer pressure (90.4%), Internet (86.7%), pornography (83.9%) and drugs (82.9%) are the leading factors which contribute to pre-marital sex among undergraduates. CONCLUSION: The study hereby recommends that Parents should as a matter of responsibility monitor and pays regular visits to their children in the universities and provide them with materials that will make them stay comfortable for them not to fall victim to peer pressure.Pre-marital sex is a practice that should be avoided by undergraduate students, though most students consider courtship as a normal practice, it is still used as a normal factor that leads them to practice pre-marital sex.