A special-purpose hardware device for mitigating motion-to-photon latency in head-mounted displays may include an image signal processor that receives at least one image frame captured by a camera device of a head-mounted-display system. The special-purpose hardware device may also include an input-formatting component that receives the computer-generated imagery. The special-purpose hardware device may further include a blending component that generates at least one mixed-reality frame by overlaying the computer-generated imagery onto the image frame. The special-purpose hardware device may additionally include a frame-output interface that feeds the mixed-reality frame generated by the blending component to a display device of the head-mounted-display system to facilitate displaying the mixed-reality frame for presentation to a user wearing the head-mounted-display system. Various other apparatuses, systems, and methods are also disclosed.