We report the performance of UiO-66 and its Brønsted acid functionalized derivative, UiO-66-(COOH)2, as heterogeneous catalysts for levulinic acid esterification with ethanol. Importantly, compared with UiO-66, UiO-66-(COOH)2displayed superior catalytic performance (up to 97.0 ± 1.1% yield of ethyl levulinate) attributed to the synergistic effect between Lewis acidic Zr clusters and Brønsted acidic −COOH groups. Furthermore, UiO-66-(COOH)2was stable and reusable without an appreciable loss in catalytic activity for at least five consecutive cycles. This study demonstrates that the interplay of Brønsted and Lewis acid sites in zirconium metal–organic frameworks leads to more efficient catalytic conversion of a biomass feedstock to biofuel, and with further hypothesis driven research, additional materials that show promise as candidates for catalytic conversion of biomass feedstocks to biofuels and valuable chemicals can be developed.