This study investigated the relationship between parental behaviour and delinquent behaviour among senior secondary school students in Delta State. The study was guided by four research question and four research hypotheses. The correlational research designed was used. The target population for the study was 40,329 senior secondary school two (SS2) students in Delta State and the sample size of 380 students were selected using multi-stage and simple random sampling technique. The questionnaire was the instrument used for data collection, titled: "Parental Behaviour and Delinquent Behaviour Scale” (PBDBS). The reliability test using the Cronbach’s alpha reliability coefficient yielded the following coefficient; 0.91 for parental behaviour scale, and 0.83 for delinquent behaviour. The data obtained in the field were analyse using Pearson Products Moments Correlation (PPMC) to answer the research questions while Simple Regression Statistics was used to test the corresponding null hypotheses at 0.05 level of significance. The findings revealed parental behaviour showed no significant relationship with delinquent behaviour, aligning with the study's expectations. However, the study found no significant relationship between sex, location and delinquent behaviour. The study concludes that parental behaviour plays significant impact on adolescents' engagement in delinquent activities and that sex, location factors may not play a direct role in shaping adolescents' engagement in delinquent activities. The study recommends amongst others that; education and support programs for parents to enhance their parenting skills and increase positive parental involvement in their children's lives should be supported. Partnerships between schools, families, community organizations, and mental health professionals to create comprehensive support networks for adolescents should be implemented. Cultural and contextual factors when designing interventions and support programs should be considered.