We show that transfer hysteresis for a pentacene thin film transistor (TFT) with a low-temperature solution-processed zirconia (ZrO_x) gate insulator can be remarkably reduced by modifying the ZrO_x surface with a thin layer of crosslinked poly(4-vinylphenol) (c-PVP). Pentacene TFTs with bare ZrO_x and c-PVP stacked ZrO_x gate insulators were fabricated, and their hysteresis behaviors compared. The different gate insulators exhibited no significant surface morphology or capacitance differences. The threshold voltage shift magnitude decreased by approximately 71% for the TFT with the c-PVP stacked ZrO_x gate insulator compared with the bare ZrO_x gate insulator, with 0.75 ± 0.05 and 0.22 ± 0.03 V threshold voltage shifts for the bare ZrO_x and c-PVP stacked ZrO_x gate insulators, respectively. The hysteresis reduction was attributed to effectively covering hysteresis-inducing charge trapping sites on ZrO_x surfaces.