Maternal health service delivery remains a critical public health concern in Kenya, particularly in arid and semi-arid regions such as Isiolo County, where socio-cultural practices, limited healthcare resources, and geographical challenges continue to affect access to quality maternal healthcare. This study investigated the influence of socio-cultural factors on maternal health service delivery in Isiolo County, Kenya. Specifically, the study examined the effects of cultural beliefs and practices, gender and family decision-making dynamics, community norms and social support systems, and traditional maternal health practices on maternal health service delivery. The study adopted a mixed-methods descriptive cross-sectional research design. The target population comprised 207 respondents, including 5 hospital administrators, 42 healthcare providers, and 160 maternal healthcare service users attending selected public healthcare facilities in Isiolo County. A census approach was employed, where all eligible respondents available during the data collection period were included in the study. Data were collected using structured questionnaires and key informant interviews and analyzed using descriptive statistics, correlation analysis, and multiple linear regression at a 5% significance level. The findings revealed that socio-cultural factors had a positive and statistically significant influence on maternal health service delivery (β = 0.684, t = 16.107, p < 0.000). Cultural beliefs and practices, gender and family decision-making dynamics, community norms and social support systems, and traditional maternal health practices significantly influenced the accessibility, utilization, and quality of maternal healthcare services. The study concluded that socio-cultural factors play a crucial role in shaping maternal health service delivery in Isiolo County. The study recommended strengthening community sensitization programs, promoting male involvement in maternal health, addressing harmful cultural practices, enhancing community support mechanisms, and fostering collaboration between healthcare providers and community leaders to improve maternal health outcomes and service utilization.