Wearable sensors are the technology of the future and will become an integral part of daily life. These sensors can monitor the physical activities and biochemical information of an individual, organ functions, and environmental changes. A wearable sensor may comprise a sensing element, electrodes, substrate, power unit and data processing unit. Selectivity, sensitivity and reliability of a wearable sensor depend on the sensing element, electrodes and substrate, which can be designed/fabricated with a suitable material. A variety of materials including carbon materials, conductive polymers, metal oxides, metals, elastomers, and nanomaterials have been used depending on the applications of the sensor. In this review, we will summarize the recent developments regarding the use of advanced materials for applications in wearable sensor technologies.