Background: Healthcare workers face high levels of stress, long hours and demanding workloads, which can impair sleep, mental health and job performance. Aerobic exercise has been shown to improve these outcomes by enhancing mood, reducing stress and promoting better sleep. Exploring the effects of aerobic exercise on sleep quality, mental health, and job performance among healthcare professionals is necessary. Aim of the Study: To determine the effects of aerobic exercises on job performance, mental health and sleep quality among interns in Federal Medical Centre, Owo. Material and Methods: This pretest-protest study design involved 40 physically fit healthcare interns at Federal Medical Centre, Owo selected through consecutive sampling. Participants engaged in supervised aerobic exercise sessions; three times weekly for six week, each lasting 40 minutes. Pre and post intervention data were collected using the Werwick-Edinbugh Mental well-being Scale (WEMWBS), Pittsburgh sleep quality index (PSQI), and the Minnesota Job Satisfaction Questionnaire (MJSQ). Data were analyzed using Statistical Package for Social Sciences (SPSS) version 26 with Wilcoxon signed-rank test applied to assess pre-and post- intervention differences at a 0.05 significance level. Results: A total of 37 interns (mean age= 25.54 ± 2.40 years) completed this study. Pre and post intervention comparison of results showed no significant difference in mental well-being (p=0.219) and job satisfaction (p=0.158). However, a significant difference was observed in sleep quality of participants (p=0.001), indicating better sleep quality. Conclusion: Aerobic exercise significantly improved sleep quality, with positive trends (though not significant) in mental well-being and job satisfaction.