Mechanical low pass filters for motion sensors and methods for making the same are disclosed. In an implementation, a motion sensor package comprises: a substrate; one or more viscous dampers formed on the substrate; one or more mechanically compliant metal springs formed on the substrate; and a sensor stack attached to the one or more metal springs, the sensor stack overlying the one or more viscous dampers and forming a gap between the sensor stack and the one or more viscous dampers and channels between the one or more viscous dampers and metal springs, wherein the one or more metal springs and the one or more viscous dampers provide a mechanical suspension system having a resonant frequency that is higher than a sensing bandwidth of a motion sensor in the sensor stack and lower than a resonant frequency of the motion sensor.