This study seeks to investigate the impact of fiscal and monetary policy on economic growth in Southern African Custom Union (SACU) member economies between 1980 and 2017. Government expenditure and revenue were used as the proxy variables for the fiscal policy whereas real interest rate, inflation, official exchange rate and M2 money supply were used as the proxy variables for monetary policy. Using Lin, Levin and Chu (LLC), and Im, Peresan and Shin (IPS) unit root tests, it was found that all variables were stationary at level except for M2 money supply which was found to be stationary after first difference. Due to this, Panel Auto Regression Distributed Lags (PARDL) estimation technique was utilized in this study. Pooled Mean Group (PMG) PARDL model estimator was used in this study. The results indicate that fiscal and monetary policy influence economic growth significantly in the long run. However, fiscal policy is only significant if government expenditure is used as the functional policy instrument rather than government revenue. In the short run, the effects of these two macroeconomic policies on economic growth are mixed. Granger causality results indicate that the direction government expenditure, real interest rate, inflation and official exchange rate Granger cause economic growth. These causality links are unidirectional in nature. Lastly, the results also indicate that private investment is crowded out in the long run because of significant high levels of government expenditure in the long run across SACU member economies. In the short run, private investment is crowded out because of significant high level of government expenditure only in Swaziland. As some of the recommendations of this study, SACU member governments should redirect their public expenditures into investing more in human capital. Investing in human capital, among other factors can include empowering the active unemployed population with relevant skills that meet labor markets for easy employment. In that case, the tax revenues would increase which could play an important role in reducing government budget deficits. Furthermore, SACU member economies' central banks can make monetary policy more effective by using monetary accommodation. Hence, when the governments apply expansionary fiscal policy, the central banks can increase money supply to avoid interest rates from increasing (monetizing budget deficit).