Thin‐film transistors (TFTs) grown on a flexible glass substrate using single‐crystal‐like germanium (Ge) channel to simultaneously achieve high carrier mobility, high performance characteristics, mechanical flexibility, and cost‐effective large‐area manufacturing are reported. High‐crystalline‐quality materials of biaxially textured CeO2 deposited at room temperature by ion‐beam‐assisted deposition followed by single‐crystal‐like Ge epitaxially grown at 550 °C by plasma‐enhanced chemical vapor deposition on an amorphous substrate are developed. p‐type Ge with {111} surface shows well‐aligned grains in both out‐of‐plane and in‐plane directions, as characterized by reflection high‐energy electron diffraction, X‐ray diffraction, and Raman spectroscopy. The material structures are fabricated to transistor devices with top‐gate geometry. The devices (channel width and length = 80 and 14 μm) exhibit performance characteristics with on/off ratio of ≈106, a field‐effect mobility of ≈105 cm2 V−1 s−1, and saturation current levels of ≈3.5 mA, which are significantly higher than performance metrics of other state‐of‐the‐art TFTs based on amorphous Si, organic semiconductors, and semiconducting oxides. This development can open a new avenue for next‐generation TFTs beyond the display applications.