The residual effects of organic mulches on soil fertility and crop yield are underexplored in the Derived savannah soils of southeastern Nigeria. This study investigated the residual influence of selected organic mulch materials on the physico-chemical properties of soil and the yield of yellow pepper (Capsicum chinense) one year after the application. The research was conducted at the Department of Soil Science and Land Resources Management Research Farm, Nnamdi Azikiwe University, Awka. The experimental design was a Randomized Complete Block Design (RCBD) with four treatments (oil palm fiber – OPF, rice husks – RH and neem leaves – NL – Azadirachta indica A. Juss. and a control), replicated five times. Soil samples collected at 0-15 cm were analyzed using standard analytical procedures; data on plant parameters were also collected. The collected data were subjected to Analysis of Variance (ANOVA) using Genstat 4th edition, means were separated using the Least Significant Difference at a 5% level of probability. Results indicated that NL significantly enhanced soil pH, total nitrogen, available phosphorus, calcium, magnesium, effective cation exchange capacity, and base saturation. In contrast, RH improved soil organic carbon and resulted in the highest fruit yield (2.2 t/ha). NL enriched soil fertility more effectively than the other mulches, likely due to the favorable decomposition and nutrient release patterns of both OPF and RH. This study recommends RH and NL as the cost-effective and locally available mulching options for sustainable pepper production in southeastern Nigeria.