This study explores the performance tuning of flexible InGaZnO (IGZO) thin-film transistors (TFTs) using a double-gate configuration. DC analysis on individually controllable double-gate TFTs highlights that the bottom-gate biasing is highly effective in facilitating efficient switching of the devices, whereas the top-gate biasing allows for controlling their performance. This is demonstrated for the ac response of the devices with different channel lengths showing the tunability of f T and f MAX with a maximum relative tuning up to 130% for f T and 170% for f MAX. A more efficient control is observed for longer TFTs, resulting in increased characteristics frequency up to 50%. Furthermore, the effect of the performance tunability is also reported even when the double-gate TFTs are exposed to tensile strain induced by a bending radius of 2 mm. These findings indicate new possibilities for the design of flexible analog systems with dynamically adjustable performance.