To satisfy consumer demand for ultrahigh-speed wireless communication, oscillator in the D-band using CMOS as well as compound semiconductors are under development. However, the phase noise is large because a small device is used to achieve a high operating frequency. In the D-band oscillator, suppressing 1/f noise is effective in the improving the phase noise. In this study, a 116GHz CMOS injection locked oscillator (ILO) with 99.3dBc/Hz at 1MHz offset phase noise is proposed. To improve the phase noise, a master-slave topology and injection locking are used. The circuit is fabricated by 65nm 1P12M CMOS process. The core size of the chip is 530×520m2 including pads. At a supply voltage of 0.6V, the phase noise was 99.3dBc/Hz at 1MHz offset, and the power consumption was 1.45mW. The oscillator can be tuned from 116.05 to 116.57GHz. The FOM of the proposed ILO is 18.7dB higher than those of previously reported oscillators.