Techniques are disclosed herein for ferroelectric-based field-effect transistors (FETs) with threshold voltage (VT) switching for enhanced RF switch transistor on-state and off-state performance. Employing a ferroelectric gate dielectric layer that can switch between two ferroelectric states enables a higher VT during the transistor off-state (VT,hi) and a lower VT during the transistor on-state (VT,lo). Accordingly, the transistor on-state resistance (Ron) can be maintained low due to the available relatively high gate overdrive (Vg,on−VT,lo) while still handling a relatively high maximum RF power in the transistor off-state due to the high VT,hi −Vg,off value. Thus, the Ron of an RF switch transistor can be improved without sacrificing maximum RF power, and/or vice versa, the maximum RF power can be improved without sacrificing the Ron. A ferroelectric layer (e.g., including HfxZryO) can be formed between a transistor gate dielectric layer and gate electrode to achieve such benefits.