A sensor cover according to embodiments of the disclosure is capable of being used with a non-invasive physiological sensor, such as a pulse oximetry sensor. Certain embodiments of the sensor cover reduce or eliminate false readings from the sensor when the sensor is not in use, for example, by blocking a light detecting component of a pulse oximeter sensor when the pulse oximeter sensor is active but not in use. Further, embodiments of the sensor cover can prevent damage to the sensor. Additionally, embodiments of the sensor cover prevent contamination of the sensor.