In this paper, an ultra-low-power, inverter-based, universal Gm-C filter is proposed. The proposed filter benefits from the orthogonal tunability of center frequency (f0) and quality factor (Q) and is designed using 180 nm TSMC technology node parameters. To significantly reduce the proposed filter's power consumption, all transistors are biased in the subthreshold region at a 0.7 V supply voltage. Additionally, the quality factor and center frequency of the proposed filter are varied by the variations of the capacitance parameters. The power consumption for the proposed Gm-C filter is 215 nW at the center frequency of 4.5 kHz.