The railing suspension apparatus allows a user to detachably attach a variety of items while suspending an item from a railing. The apparatus includes a brace, an offset arm, a cantilever, and a hanger. The brace includes a main body and a post-receiving slot. The post-receiving slot traverses into the main body. The brace prevents the present invention from sliding along the railing. The offset arm is positioned perpendicular to the post-receiving slot and terminally connected to the offset arm opposite to the body. The offset arm positions the cantilever and hanger about the brace. The cantilever and the post-receiving slot is oriented opposite to each other, allowing the cantilever to rest on the railing while being pushed by the weight of the item engaged with the hanger. The hanger is terminally connected to the cantilever, opposite to the offset arm.