ABSTRACT This study examines the effect of transport costs on agricultural market access among smallholder farmers in Homabay County, Kenya. Anchored in Spatial Economics Theory, the research employed a quantitative correlational design, collecting data from 350 respondents (smallholder farmers) across the county's sub-counties using structured questionnaires. A stratified random sampling approach ensured balanced representation, achieving an 88% response rate (n=308). Findings revealed a strong negative and statistically significant relationship between transport costs and market access (r=-0.698, p<0.01). Regression analysis indicated that transport costs account for 49% of the variance in market access (R²=0.49). The regression coefficient (β=-0.675, p<0.001) confirmed that a one-unit increase in transport costs leads to a 0.675-unit decrease in market access. These results support the rejection of the null hypothesis, confirming a significant negative effect of transport costs. The study concludes that elevated transport costs, stemming from poor road conditions, seasonal fluctuations, long distances, and limited options, substantially hinder market availability, price realisation, sales volumes, access to information, and timely deliveries, thereby constraining economic opportunities in this underdeveloped rural setting. It recommends strategic investments in resilient rural infrastructure, subsidies for fuel and shared transport, and digital tools for market linkages to bolster smallholder resilience and integration. Keywords: Transport Costs, Market Access, Smallholder Farmers, Rural Infrastructure, Spatial Economics.