Early marriage is increasingly recognized both as a violation of human rights and as an impediment to the development, wellbeing and life options of affected individuals and their children. Despite intervention programs in Kenya by the state, national and international communities, and presently the county government, early marriage prevalence rates in Homa Bay County have persistently remained high over the years. This has led to early childbearing, with significantly higher maternal mortality and morbidity rates, as well as, higher infant mortality rates. It also virtually puts an end to young people’s education in addition to being constrained in their ability to overcome poverty. Hence, the study was set to assess the demographic dynamics and spatiotemporal dimensions of first nuptial age among men and women in Homa Bay County, Kenya. The specific objectives included; 1) to investigate the spatiotemporal dimensions of marriage formation and their relationship with early marriages; 2) to determine the forms of demographic dynamics and their relationship with early marriages and; 3) to assess the roles of key stakeholders in curbing early marriages and the extent to which their level of activities influences delayed marriages. The research was guided by the two theories of family change. The study employed a cross sectional survey research design to collect data. Primary data was directly collected using structured questionnaires, Focus Group Discussion guides and in-depth interview guides. A multistage sampling procedure was applied to select 420 respondents out of 371,891 for the study at 0.05 confidence interval. The quantitative data was analyzed using logit regressions, cross tabulation, Kaplan Meier Survival Analysis, geospatial mapping, Quantum GIS and path analysis while qualitative data was analyzed using thematic technique. Of all the 420 household heads, 106(48.6%) of women and 17(8.3%) of men had married early. Results show that geographical region had no substantial influence on age of first marriage, because all the sub-counties are culturally homogeneous in the marriage patterns. The Coefficient of Determination (R2) for the equation level goodness of fit shows that the spatiotemporal dimensions explain 49% of the variation in first nuptial age. The most important factors (in order of importance) were age at first sexual debut (-2.5), premarital contraceptive use (-1.8), ex-nuptial birth (-1.3) and childhood place of residence (0.8). Furthermore, 34% of the total variance (R2) in the dependent variable was accounted for by the indirect and direct combination of the family background characteristics. Key variables in order of largest contribution to first nuptial age were, number of media exposure (-2.6), family wealth (-2.4), household structure (1.7) and natal parity size (1.4). The indirect and direct combination of the individual socio-economic factors accounted for 43% of the variation (R2) in first nuptial age. The most important factors (in order of importance) were household wealth (-2.4), form of marriage (-1.4), followed by children ever born (-1.3) and religion (-0.9). While majority (73.5%) of the respondents knew the legal age of marriage and that there is a legal law prohibiting early marriage, the details of how it is implemented were not widely comprehended. There was a general less awareness (34.4%) around the provisions, the prescribed penalties and punishment of the legal instruments. The study recommended that the proposed integrated delaying nuptial age policy model be adopted by the county and the national government with coordinated strategies, action and resources to end early marriages and enable every adolescent to thrive. They should adopt and use the policy model to engage communities, families and policymakers, while imparting life and social skills, opportunities, sensitization, sexual and health education, and economic empowerment to adolescents to prevent the risk of early marriages.