Highly stretchable supersensitive sensors represent a new epoch in the field of intelligent medical devices. Applications include the detection of various stimuli of the human body and environmental monitoring around biological surfaces. To provide more accurate measurement results, stretchable sensors must be tightly attached on the skin surface or to clothing. Consequently, stretchable sensors must fulfill many requirements, such as high stretchability, high comfortability, high sensitivity, and long-term wear. To address these challenges, investigators have devoted considerable research effort to the development of technology, and much progress has been achieved. Here, recent developments with stretchable sensors are described, including human motion monitoring sensors, vital sign monitoring sensors, and sensors for environmental monitoring around biological surfaces. The latest successful examples of supersensitive sensors for achieving stretchability by novel materials or structures are reviewed. In the next section, recent advances regarding processing technology innovations are introduced. Future research directions and challenges in developing a highly stretchable supersensitive sensor for wearable biomedical applications are also discussed. With the development of new materials and novel technologies, and given the interdisciplinary nature of the research, the functionalities of stretchable sensors will become more powerful, and stretchable sensor technology will become more mature.