Output response to discretionary fiscal policy is a key aspect of examining various theories, findings of empirical studies and delivering guidance to policymakers. This study analyses the output response to unanticipated fiscal spending shocks under several structural economic characteristic factors, including business cycle states, debt burden, openness of the economy, exchange rate regimes and political governance regime, using annual data from 40 countries in SSA spanning from 2000 to 2019 in a panel threshold vector auto‐regression model. The findings indicate that fiscal spending multipliers have much larger effects on output in times of recession, in economies operating under lower trade openness, a fixed exchange rate, low‐debt burden, restricted capital mobility, less financial development and a democratic governance regime. Based on the results, the discretionary countercyclical fiscal policy and optimal fiscal policy action are recommended. Moreover, in order to have effective fiscal policy must target hand‐to‐mouth consumers (non‐Ricardian consumers) and firms with limited liquidity, concentrating on social services and social protection to increase short‐term demand. Likewise, A proper fiscal monetary policy mix should be considered with other structural measures to maximising the positive effects of the fiscal expansion.