This Letter presents a millimetre-wave CMOS oscillator, which achieves 4.9 dBm output power with 16% peak power efficiency. A phase noise of −98 dBc/Hz at 1 MHz offset frequency and 26.7% tuning range around 57.5 GHz centre frequency were verified experimentally. To t̰he best knowledge of the authors, the output power, efficiency, and phase noise performance are the best among fundamental CMOS oscillators in the frequency range of interest, while the tuning range is the third highest result reported to date. The circuit occupies a silicon area of ~9000 mm² without the matching inductors on a 22 nm fully depleted silicon on insulator (FD-SOI) CMOS technology.