Innovation capacity has emerged as a critical determinant of sustainable development, yet Uganda continues to face persistent challenges in generating transformative solutions despite investments in infrastructure, technology, and capacity building. This study examined the role of cultivating a questioning culture—characterized by "why" and "what if" thinking—as a strategic driver of innovation within Uganda's development pathway. Employing a convergent parallel mixed-methods design, the research surveyed 847 participants comprising students (n=412), entrepreneurs (n=285), and professionals (n=150) across Uganda's four regions, while conducting 36 in-depth interviews and 8 focus group discussions with key informants from education, entrepreneurship, public service, and civil society sectors. The sample size was calculated to detect medium effect sizes with 80% statistical power. Quantitative analyses including descriptive statistics, correlation analysis, multiple regression, and structural equation modeling were complemented by thematic analysis of qualitative data using NVivo 12 software. Results revealed significant sectoral disparities in questioning culture, with entrepreneurs demonstrating the highest questioning frequency (M=3.68, SD=0.76), followed by professionals (M=3.12, SD=0.89) and students (M=2.84, SD=0.92), F(2,844)=47.32, p