Thermoset polymers with dispersed carbon nanotubes (CNTs) can be rapidly cured via microwave irradiation due to the nanofiller’s high microwave absorption and efficient conversion of radiant energy to thermal energy. In this paper, polydimethylsiloxane (PDMS) containing dispersed CNTs was cured by either microwave irradiation or traditional convection heating. The mechanical, electrical, and piezoresistive properties of the fabricated flexible nanocomposites containing various levels of CNTs were experimentally characterized. Experimental results demonstrated that the microwave curing method was able to reduce the curing time of PDMS/CNT nanocomposites by at least 96% and enhance the electrical conductivity by almost 150% compared to oven curing. In addition, the microwave cured nanocomposites were found to have a significantly reduced compressive modulus in comparison to the oven cured counterparts. Piezoresistive characterization tests were performed to fully characterize the sensing performance of the nanocomposite in compression. Cyclic compressive tests identified that the piezoresistive sensitivities of the nanocomposites were nearly identical irrespective of the curing method used. Lastly, the rapidly fabricated piezoresistive sensor was tested as a wearable sensor to measure the pressure applied to the foot and hand during normal human actions.