This paper presents a low power mmWave Class-F234 voltage controlled oscillator (VCO) with a multi resonant Inductor-Capacitor (LC) tank. The proposed VCO designed in 40 nm CMOS technology, shows a 24.5 - 29.5 GHz continuous tuning. The VCO shows phase noise of -103 dBc/Hz and -116 dBc/Hz at 1 MHz and 10 MHz offset, respectively at 27.86 GHz while consuming 2.5 mW power at 0.5 V. FoMT of 186.7 dB has been obtained at 1 MHz offset. The tuning range is 18.5 % and the oscillator occupies 0.094 mm2 .