Background: Infant mortality, measured as the summation of neonatal and post-neonatal mortalities, remain unacceptably high in Kakamega Central Sub-County, Kakamega County, Kenya. Reducing infant mortality is paramount not only in assessing the progress made towards the third sustainable development goal but also in creating a conducive environment for fertility reduction and in giving a chance to new-born babies to live out their social and economic potential in their families and societies at large. Objective: This study sought to establish the influence of socioeconomic and demographic factors on rural – urban disparities in infant mortality in Kakamega Central Sub - County, Kakamega County, Kenya. Methods: A cross-sectional research design was used. Systematic random sampling was employed to obtain a sample of 422 mothers within the reproductive age range of 15 to 49 years. Purposive sampling was used to arrive at key informants that were engaged in the study. Primary data were collected from December 2022 to January 2023 by administering pretested and validated questionnaires and interviewing key informants. Descriptive statistics and multinomial logistic regression analyses were conducted on the Statistical Package for Social Sciences computer software to estimate the prevalence of infant mortality and the odds ratio used as a measure of association at ρ<0.05. Results: Results of multivariate analysis indicated that there were higher likelihoods of rural neonatal (aOR = 1.913) and urban post-neonatal (aOR = 3.823) mortalities amongst mothers with no education qualifications. There were reduced likelihoods of rural post-neonatal (aOR = 0.105) and urban neonatal (aOR = 0.108) mortalities amongst mothers working in the professional, technical, managerial and clerical sectors. Both young (aOR = 1.579 for neonatal mortality) and old (aOR = 2.742 for infant mortality) ages at motherhood, and first births (aOR = 3.492 for infant mortality) and births of high orders (1.881 for neonatal mortality) were associated with increased likelihoods of mortalities in urban and rural areas, respectively. Urban mothers who observed a ≤ 24 months wait period prior to an index birth were more likely to report both post-neonatal (aOR = 3.294) and infant (aOR = 3.616) mortalities. Conclusions: The major contributors to the rural - urban disparities in infant mortality in Kakamega Central Sub-County were order of the index birth, which was significant only in rural areas, and wait period prior to the index birth, which was significant only in urban areas, after controlling for the confounding variables. It is important to advocate for childbearing during the middle reproductive ages and widen the wait period between successive births so as to improve the maturity of the mother and reduce parity, both of which correlate with low infant mortality. Future studies should be done on the relationship between marital status of the mother and infant mortality.