This study examined the relationship between economic development sustainability and market opportunity utilization in agritourism across selected municipalities in Laguna, namely Calauan, Liliw, Nagcarlan, and Pila. Anchored in Romer’s Endogenous Growth Theory and the Theory of Entrepreneurial Opportunity Identification and Development, the study explored how internal growth drivers, such as human capital development, innovation and technology adoption, and knowledge spillovers, influence entrepreneurial alertness, social networks, and opportunity belief formation among agritourism enterprises. A quantitative descriptive-correlational design was employed, with data collected from 96 agritourism owners and managers selected through random sampling from a population of 280. Data were gathered using a validated four-point Likert scale questionnaire and analyzed through descriptive statistics and Pearson’s product-moment correlation coefficient. Findings indicate that economic development sustainability was fully sustained, particularly in innovation and technology adoption with a mean of 3.49 and a standard deviation of 0.753, and in human capital development with a mean of 3.39 and a standard deviation of 0.811, while knowledge spillovers also demonstrated a fully sustained level with a mean of 3.32 and a standard deviation of 0.688. Market opportunity utilization was fully utilized, with entrepreneurial alertness showed a mean of 3.40 and a standard deviation of 0.707, social networks with a mean of 3.41 and a standard deviation of 0.777, and opportunity belief formation with a mean of 3.51 and a standard deviation of 0.605. Correlation analysis revealed a statistically significant positive relationship between economic development sustainability and market opportunity utilization. The findings underscore the role of sustained investments in human capital, innovation, and collaborative practices in enhancing entrepreneurial capability and market responsiveness.