A novel surface-micromachined non-contact high-angular-speed sensor with total surface area under 4 mm2 was developed using the multi-user MEMS processes (MUMPs), and was integrated with a commercial RF transmitter with carrier frequency of 433 MHz for wireless signal detection. This piezoresistive sensing system is capable of wirelessly measuring rotation speeds with sensitivity of ∼2 Hz/rpm/V using 5 V input in the 100–6000 rpm rotation range. Further experimental analyses showed that a sensor designed with a 13 μg seismic mass has high enough sensitivity to detect angular position of a rotating disk if the disk rotation axis is tilted away from the vertical direction. Experimental results from simultaneous detection of angular position and average angular speed for the sensor are reported in this paper.