There exist mixed evidential outcomes on the effect of external debt on economic growth. Withrnhigh saving gaps in low-income SSA countries, it seems plausible that external borrowing canrnaffect growth positively if well utilized or negatively as the debt becomes a burden. As a result,rnthe purpose of this study is to examine the effect of external public debt on economic growth andrnto assess the debt sustainability of twenty-four SSA countries over the period 2000-2017 usingrndescriptive trend analysis and panel data analysis. The trend and descriptive analysis assessedrnthe behavior of external public debt and economic growth while the empirical analyses employedrnpanel data regression in which a fixed effect model is estimated. The study found that externalrnpublic debt, external public debt service, and trade openness have a negative and significantrneffect on the economic growth of low income SSA countries. However, investment and domesticrndebt have a positive and significant impact on the economic growth of the countries that thernstudy covers. Additionally, the inflation rate and population growth have no significant effect onrneconomic growth. For the purpose of examining the debt sustainability of chosen countries,rnvarious tests were undertaken. The study concludes that the external debt of low income SSArnnations is unsustainable. In light of these findings, selected SSA countries should adopt arnbalance between external and domestic debt to ensure sustainable economic growth. Theyrnshould also implement measures to promote export and expand domestic investment.