A 30 GHz wide locking range injection-locked frequency divider based on 55 nm CMOS process for millimeter-wave phase-locked loop was proposed to overcome the problem of narrow locking range of traditional injection-locked frequency dividers. Distributed direct injection and high-order transformer resonator were applied to the frequency divider to increase the injection current and injection efficiency, thus achieving wide locking range without tuning mechanisms. Harmonic suppression technique was also adopted to the output buffer to improve the locking range with no penalty in power consumption. The post simulation results show that the locking range of the proposed frequency divider was 22.8-36.3 GHz (45.7%) at the injection power of 0 dBm and the power dissipation of core circuit was 3.54 mW.