A ladder caddy assembly includes a box that has a sloped side that is positionable against a back set of legs of a folding ladder when the folding ladder is deployed. A mount is coupled to the box and the mount comprises a leg and a foot. The leg rests on a top step of the ladder for retaining the box on the ladder. The foot rests against a front set of legs of the ladder to inhibit the box from sliding away from the ladder. A pair of stops is each coupled to the box. Each of the stops abuts against the back legs of the ladder thereby inhibiting the box from sliding laterally off of the ladder.