This paper investigates the relationship between religious diversity and financial market efficiency through an empirical analysis spanning multiple (50) countries and time periods. Utilizing a comprehensive dataset compiled from various sources, including religious demographics and financial market indicators, we employ advanced econometric techniques to examine the impact of religious diversity on market efficiency. Our findings suggest a nuanced relationship between religious diversity and financial market dynamics, with significant implications for investors, policymakers, and societal stakeholders. The analysis reveals that regions characterized by higher religious diversity tend to exhibit lower levels of market efficiency, as measured by volatility, liquidity, and price informativeness. Furthermore, our results indicate that religious diversity and market efficiency vary across religious denominations and geographical regions. Our research's implications extend beyond finance, offering insights into the broader societal implications of religious diversity and its impact on economic outcomes.