In this paper, a Gm-C LPF utilizing common-mode feedforward (CMFF) CMOS inverter type operational transconductance amplifier (OTA) has been designed and verified by circuit simulations. The CMFF CMOS inverter OTA was optimized for wide input linearity and low current consumption using a standard 0.18 ${mu}m$ CMOS process; gm of 100 ${mu}S$ and current of 100 ${mu}A$ at supplied voltage of 1.3 V. Using this optimized CMFF CMOS inverter type OTA, an elliptic 5th order Gm-C LPF for GPS specifications was designed. Gain and frequency tuning of the LPF was done by changing the internal supply voltages. The designed Gm-C LPF gave pass-band ripple of 1.6 dB, stop-band attenuation of 60.8 dB, current consumption of 0.60 mA at supply voltage of 1.2 V. The gain and frequency characteristics of designed Gm-C LPF was unchanged even though the input common-mode voltage is varied.