A collapsible cart-trailer includes a folding mechanism that folds the cart-trailer into a small form factor, at least two wheels, modular, and removable and compartmentalized storage. The collapsible cart-trailer is operable in a cart mode and a trailer mode. In the trailer mode, the cart-trailer may be coupled to a movable object by a collapsible, length adjustable tow bar. In the cart mode, the cart-trailer includes a collapsible handle.