Financial integration has become a key component of development strategies in emerging economies such as India, linking domestic financial markets with the global financial system through greater capital mobility, foreign investment, and financial liberalization. Since the economic reforms of 1991, India has progressively eased capital flow restrictions, promoted foreign direct investment (FDI) and foreign portfolio investment (FPI), and strengthened domestic financial markets. While financial integration has improved access to international capital, enhanced liquidity, and supported economic growth, it has also increased exposure to global financial cycles, external shocks, exchange rate volatility, and sudden capital flow reversals, posing challenges for macroeconomic stability and monetary policy. This study examines the relationship between financial integration, financial stability, and macroeconomic performance in India using annual data from 2000 to 2023. Drawing on the finance–growth literature, it analyzes short-run and long-run linkages between Indian stock market indices (Sensex and Nifty) and key macroeconomic variables such as industrial production, money supply, inflation, interest rates, exchange rates, oil prices, gold prices, and global market indicators. The econometric framework employs Augmented Dickey-Fuller (ADF), Phillips-Perron (PP), and KPSS unit root tests, followed by the Johansen-Juselius co-integration technique and a Vector Error Correction Model (VECM). Empirical results confirm a long-run co-integrated relationship between stock market indices and major macroeconomic variables, highlighting strong interdependence between financial markets and real economic activity. The study emphasizes the need for strong regulation, prudent macroeconomic policies, and resilient financial institutions to ensure sustainable and stable economic development.