This study evaluated sexual and reproductive health communication (SRHC) between dyads of parents and their in-school adolescents in urban and rural areas of Osun State, Nigeria. A descriptive cross-sectional design was used to determine and compare the prevalence, pattern, level, triggers, and methods of SRHC between 625 parents and their in-school adolescents. Respondents were recruited using the multistage sampling technique, and data was collected using the mixed-method approach. Quantitative data was collected using a semi-structured questionnaire and analysed using chi-square and logistic regression tests, while the qualitative data was collected using a focus group discussion guide and analysed thematically. About 56% of parents (53% rural, 58% urban) and 69% of adolescents (68% rural, 71% urban) reported ever having SRHC. The level of SRHC was 31% for adolescents, with no significant difference by type of residence (36% rural, 33% urban, p=0.324) while for parents it was 59%, with a statistically significant difference by the type of residence (52% rural, 66% urban
p<
0.01). A two times higher odds of having a good level of SRHC with their parents was observed among rural female vs. rural male adolescents (OR = 1.9, 95% CI: 1.053 - 3.471, p = 0.033) and among urban early vs. urban late adolescents (OR = 2.2, 95% CI: 1.215 - 4.048, p = 0.009). The odds of having a good level of SRHC were three times higher among mothers (OR: 3.4, 95% CI: 1.409 - 8.422, P <
0.007) in urban areas compared to fathers in the same area. SRHC occurred between parents and adolescents in Osun State but with inherent disparities by location and gender. Interventions are required to improve the depth, frequency, and clarity of SRHC, particularly with topics related to experiencing sex. Parents, especially fathers, should be educated about the significance of SRHC and be provided with the skills to engage in early, effective, and sustained discussion with both male and female adolescents.