Emerging adulthood is a critical developmental stage marked by the transition to independence. However, there is limited research on how parenting dynamics influence autonomy development among Nigerian emerging adults. This study investigated whether helicopter parenting and parent-child alienation would be associated with autonomy in a sample of emerging adults at Lead City University, Ibadan, Nigeria (N = 432; aged 15 to 25 years, Mean = 19.89, SD = 3.16). Standardised instruments were used, including the Multidimensional Helicopter Parenting Scale (MHPS), Inventory of Parent and Peer Attachment (IPPA), and Adolescent Autonomy Questionnaire (AAQ). Hypotheses were tested using Pearson correlation and hierarchical multiple regression at a 0.05 level of significance. Results revealed that helicopter parenting and parent-child alienation jointly predicted autonomy (F(9,128) = 12.26, R = .48, R² = .23, p < .001). Independently, life goal autonomy (β = 0.24, p < .001), overprotection (β = -0.28, p < .001), and parent-child alienation (β = -0.23, p < .001) significantly predicted autonomy. Conclusively, over-controlling parenting and emotional distance between parents and emerging adults negatively affect their sense of autonomy. It is recommended that Interventions aimed at supporting the autonomy of emerging adults during their transition to adulthood should discourage over-controlling parenting behaviours and promote strong parent-child relationships.