The present disclosure is directed to commercial vehicle loading and unloading systems, and associated systems, devices, and methods. In one embodiment, a cargo loading and unloading system includes a cargo loading and unloading assembly and/or a cargo repositioning system. The assembly includes a first mechanical arm and a second mechanical arm that are mountable at opposite sides of an opening of the trailer. Each mechanical arm includes a first portion and a second portion pivotally coupled to the first portion. The first portions are configured to vertically raise and lower the second portions and move the second portions laterally along the opening of the trailer. The second portions include rollers and are configured to support cargo on the rollers as the mechanical arms are used to hold the cargo off the ground, and to selectively convey the cargo at least partially into or out of the trailer via the rollers.