Wirelessly powered Internet-of-Things (IoT) sensors have many unique advantages compared with wire-powered or battery-based sensors. This paper presents two wirelessly powered sensors (light and temperature) facilitated by a highly compact and efficient electrically small rectenna. The IoT sensor is integrated into the rectifier circuit of the rectenna, which converts the captured AC power to DC energy. The output DC voltage of the rectifier is dependent on the variable impedance of the sensor corresponding to different discerned values. Once an acoustic alarm is attached to this sensor-augmented rectenna, a certain amount of the measured parameter (light or temperature level) can activate the alarm. The receiving antenna of the system is a modified version of a metamaterial-inspired electrically small Egyptian axe dipole (EAD) antenna. By meandering the length of the driven element, inductive impedance was achieved to directly match the receiving antenna to the capacitive impedance of the rectifier circuit. Prototypes of the wirelessly powered light and temperature sensors were fabricated and measured. Experimental results successfully demonstrated the light and temperature sensing performance. Both systems are highly compact and very thin (diameter is 0.13 λ0 and thickness is 0.002 λ0) with a ka value equal to 0.47. They are excellent representatives of WPT-driven sensors for the emerging wireless IoT applications.