Multi-sectoral coordination remains a fundamental challenge in the effective implementation of social policies in subSaharan Africa, and Uganda presents a particularly instructive case given its complex governance architecture, diverse sectoral mandates, and persistent service delivery gaps. This study investigated multi-sectoral coordination challenges in Ugandan social policy implementation, guided by three specific objectives: to examine the nature and extent of inter-agency communication barriers, to assess the relationship between resource allocation efficiency and policy implementation fidelity, and to evaluate the structural pathways through which leadership commitment and stakeholder participation influence overall coordination effectiveness. A cross-sectional survey design was employed, with data collected from 312 purposively sampled policy implementers drawn from five key social sectors — health, education, water and sanitation, agriculture, and social protection — across twelve districts in Uganda. Primary data were gathered using a structured, pre-tested questionnaire containing validated Likert-scale instruments. Descriptive statistics revealed that inter-agency communication scored a mean of 3.42 (SD = 0.87), while resource allocation efficiency recorded the lowest mean of 2.89 (SD = 1.02), suggesting persistent bottlenecks in financial coordination. Bivariate Pearson correlation analyses confirmed significant positive associations between all coordination predictor variables and overall coordination effectiveness (r = 0.714 for ICS; r = 0.632 for RAE; p < .001). A Structural Equation Model (SEM) was estimated using AMOS, yielding excellent model fit indices (CFI = 0.967; RMSEA = 0.043; CMIN/DF = 1.32), with the full model explaining 58.7% of the variance in overall coordination effectiveness. Path analysis revealed that inter-agency communication exerted the strongest direct effect (β = 0.412, p < .001), while sector overlap conflicts exerted a significant negative effect (β = −0.198, p = .001). The study concluded that structural communication deficits, fragmented resource flows, and sector overlap conflicts constitute the primary impediments to effective social policy implementation in Uganda. Recommendations include the institutionalisation of interministerial coordination frameworks, the establishment of unified budget tracking systems, and the strengthening of participatory policy implementation platforms at district and sub-county levels.