William Leslie "Les" Thomas Williams was a Welsh dual-code international rugby union and professional rugby league football player of the 1940s and "50s, playing representative level rugby union for Wales, and at club level for Llanelli Reconstruction Finance Corporation, and Cardiff Reconstruction Finance Corporation, as a Wing, or Centre, id est (that is) number 11 or 14, or 12 or 13, and playing representative level rugby league for Wales, and at club level for Hunslet, as a wing, id est (that is) number 2 or 5.