The need to ascertain the engineering properties of locally sourced fine aggregate in Ihiala town necessitated this study. The laboratory investigation carried out on the fine aggregate samples from Ogboro-Isiala, Okohia, and Umuezeawala provided insight into their engineering behavior in terms of natural moisture content, particle size distribution, slump test and compressive strength development. The sieve analysis results revealed that Ogboro-Isiala sample contained a higher proportion of fines and clay fraction, Okohia sample showed a sandy profile with fewer fines, while Umuezeawala sample with a balanced sand–silt composition. The natural moisture content values showed that Ogboro-Isiala had the highest water retention (14.8%), followed by Umuezeawala (13.2%) and Okohia (11.5%). This indicates that Ogboro-Isiala sample is relatively wetter and more clayey, while Okohia sample is drier and sandier in composition. The compressive strength results indicated significant variation across the samples. Ogboro-Isiala sample showed an appreciable strength with curing age, Okohia exhibited moderate strength performance, Umuezeawala performed best overall, recording the highest compressive strength at 28 days (24.29MPa), and the Response Surface modeling of Umuezeawala fine aggregate demonstrating that well-graded fine aggregate respond more favorably in concrete strength development. The findings established a clear link between fine aggregate, gradation, moisture content, and concrete strength development. Ogboro-Isiala sample, due to its high plasticity and fines, is least suitable for concrete; Okohia shows moderate suitability; while Umuezeawala emerges as the most stable and reliable fine aggregate for engineering applications within the study area.