Abstract: An infinitely adjustable support bracket includes an elongate upright member having an interior way and spaced opposite side walls, a rear wall and spaced front flanges defining a slot open to the interior way. An arm member extends outwardly of the slot and has an end with a plate diagonally connected thereto which is received within the interior of the upright member. The plate is slidable within the way of the upright member when the arm is swung to an upwardly inclined relation thereto and is fixed in diagonally lodged position within the upright member for load-bearing support when the arm member is substantially normal thereto, positioning opposed edges of the plate in engagement with rear and front inner surface of the upright member. A resilient spring is provided which is connected to the arm member and engages the interior of the upright member and urges return of the plate into a diagonally lodged position when the arm is swung upwardly.