The purpose of this study is to investigate the effect of foreign direct investment and official development assistance on tax burden in Jordan employing the Auto-Regressive Distributed Lags Bounds Testing (ARDL BT) co-integration approach to the data ranging from 1991 to 2018. The results indicated that there is a long-run relationship among variables. The results showed that there is a positive and statistically significant effect of the ratio of foreign direct investment to GDP (FDI) on tax burden (TB) in the long run, and a positive and statistically significant effect of the ratio of official development assistance to GDP (ODA) on tax burden (TB) in the long run. The estimation results indicate that a 1% increase in (FDI) increases (TB) by 0.53%, and a 1% increase in (ODA) increases (TB) by 1.45%. This study is the first of its kind in examining the impact of foreign direct investment and official development assistance together on the tax burden in Jordan.