Stanley James Mountain (third ¼ 1909 – death unknown) was a rugby union and professional rugby league footballer who played in the 1920s and 1930s. He played club level rugby union (RU) for Newport RFC, as a centre, i.e. number 12 or 13, and representative level rugby league (RL) for Rugby League XIII and Wales, and at club level for Huddersfield, as a wing, or centre, i.e. number 2 or 5, or, 3 or 4.