Provided is a circuit device that can appropriately detect an error in a display image in a head up display, an electronic apparatus, an error detection method, and the like. The circuit device includes an image processing circuit and a comparison circuit. The image processing circuit performs first mapping processing, which maps an input first image on a second image to be projected onto a projection target object, and second mapping processing, which converts the second image to a third image. The second mapping processing is reverse mapping processing of the first mapping processing. The comparison circuit performs comparison between the first image and the third image, and outputs the result of comparison as information for performing error detection on the second image.