Investors generally use various indicators to assess the performance of the capital market and the overall economic condition, one of which is the LQ45 Index. The movement of this index is influenced by the BI Rate, M2 Money Supply, Exchange Rate, and Inflation, which affect liquidity, market stability, and investor behavior. This study aims to examine and analyze the impact of the BI Rate, M2 Money Supply, Exchange Rate, and Inflation on the LQ45 Index on the Indonesia Stock Exchange. The research method used is a documentary study. The population and sample were taken using the time series method. The data analysis techniques used include descriptive statistical analysis, classical assumption tests, multiple linear regression analysis, coefficient of determination, and hypothesis testing. The results of the study show that the BI Rate does not affect the LQ45 Index, M2 Money Supply has a positive effect on the LQ45 Index, the Exchange Rate has a negative effect on the LQ45 Index, and Inflation has a positive effect on the LQ45 Index.