This dataset comprises measurements of particle size distribution, soil organic carbon (SOC), including SOC concentration and SOC stocks, soil structural properties (bulk density, total porosity, aggregate size distribution of water-stable aggregates, mean weight diameter, and geometric mean diameter), and soil hydraulic properties (saturated hydraulic conductivity, saturated water content, water content at field capacity, and macroporosity). Data were collected across three slope positions (upper, middle, and lower slope) within a cultivated humid tropical coastal plain sand landscape. The dataset was generated to examine the relationships among SOC, soil structural attributes, and hydraulic properties in cultivated humid tropical coastal plain sands.