This paper proposes and demonstrates a novel flexible tactile sensor for both normal and shear load detection. For the realization of the sensor, polyimide and polydimethylsiloxane are used as a substrate that makes it flexible. Thin metal strain gauges, which are incorporated into the polymer, are used for measuring normal and shear loads. The salient feature of this tactile sensor is that it has no diaphragm-like structures; therefore, it can be used as a ground reaction force sensor for balance control in humanoid robots. Four tactile unit sensors are assembled and placed in the four corners of the robot's sole. The tactile unit sensor can measure loads up to 2 kg-force. When loads are exerted on the sole, the ground reaction force can be measured by these four sensors. The measured forces can be used in the balance control of biped locomotion systems.