This paper presents a cascode amplifier for bendable analog and radio-frequency electronic systems in a flexible amorphous indium gallium zinc oxide (a-IGZO) TFT technology, featuring a minimum gate length of 5 µm. The design is optimized for large bandwidth. The circuit design was carried out with a MOSFET LEVEL=3 SPICE model template. The required model parameters were extracted from both DC and AC measured characteristics. Measurements results show 10.5 dB of voltage gain and a 3 dB bandwidth of 2.62 MHz; the small-signal performance was closely predicted by simulations. The presented circuit provides the highest frequency of operation reported for a single-stage cascode amplifier in a-IGZO TFT technology to date.