This paper examines the relationship between stock market returns and selected macroeconomic variables and examine the impact of macroeconomic uncertainty on stock market volatility in Sri Lankan stock market. Interest rate, inflation, money supply and exchange rate are selected as a set of exogenous variables to represent the macroeconomic factors that influence the stock market, returns and volatility. The sample includes monthly stock market index and macroeconomics data from 1998 to 2016 covering 228 data points. In achieving research objectives, Vector Error Correction Model (VECM) and Exponential Generalized Autoregressive Conditional Heteroskedasticity (EGARCH) models are specified and estimated. The results of Johansen Juselius cointegration test indicate a long run relationship between macroeconomic variables and stock returns. Particularly, the results of cointegration test suggest that there is a significant negative effect of Treasury bill Rate (TBR) and Exchange Rate (EXR) on stock returns while significant positive long run effect of Money Supply (MSI) / Inflation (INF) on stock returns. The Error Correction Term (ECM) in the VECM model indicates only 4.1 percent of the long run shock adjusted in the short run period and supports the argument of weak form of market efficiency in the Colombo Stock Exchange (CSE), Sri Lanka. Further, the results of the EGARCH model evidence the presence of asymmetric volatility in the monthly stock returns which suggest that the bad news in the CSE has larger effect on the volatility of the stock market than the good news. Similarly, the model establishes that interest rate and money supply create macroeconomic risk to the volatility of the stock market returns in Sri Lankan context. Accordingly, this paper, as a whole, conclusively establishes that the stock returns and market volatility are dependent on macroeconomic variables. These findings hold managerial and policy implication at least to the Sri Lankan policy makers, market regulators, investors and market analysts. The test results suggest the information inefficiency in the Colombo stock market. Further, Investors in the market should look at the systematic risks revealed by the money supply and short term interest rates when structuring portfolios and diversification strategies. Policymakers may need to take these macroeconomic variables into account when formulating economic and financial policies.