Provided is a driving assist apparatus that eases the driver's operational burden by superimposing a guide image on an image captured by a vehicle-mounted camera, with a simple system configuration. A captured image of the periphery of the vehicle captured by the vehicle-mounted camera is displayed on a display apparatus inside the vehicle as a display image superimposed with a guide image using a guide display, which is a graphics image containing a guide line. Predicted course lines, which are guide lines indicating predicted courses according to an actual steering angle of the vehicle in the captured image, are stored as a plurality of graphics images that have been generated in advance for every predetermined steering angle, in a storage portion that stores graphics images for forming guide displays. A graphics image of a predicted course line is acquired from the storage portion according to the actual steering angle of the vehicle, and is provided as a guide image.