Robert Esmond McMaster (15 January 1921 – 1 August 2003), also known by the nickname of "Wallaby Bob", was an Australian wrestler, rugby union and professional rugby league footballer. He played in the 1940s and 1950s, and was a wrestling referee in the 1960s and 1970s. He played representative level rugby union (RU) for Australia, and at club level for Brothers Old Boys, as a prop, i.e. number 1 or 3, and representative level rugby league (RL) for Other Nationalities and British Empire, and at club level for Leeds and Past Brothers, as a prop, i.e. number 8 or 10.