A shelf attachment for use with a beach or lounge chair is formed of one-piece or has a first shelf half and a second shelf half hingedly and foldably connected to the first shelf half. An elongated member extends through interlocking projections extending from the first shelf half and from the second shelf half to hingedly connect the first and second shelf halves. A first clamp assembly is secured to the first shelf half and a second clamp assembly is secured to the second shelf half to mount the shelf to the rail of a chair.