Roberto Grau (born July 16, 1970 in Mendoza, Argentina) is a retired Argentine rugby union footballer and current coach. He played club rugby in Argentina, South Africa, France and England. He also represented the Argentina national rugby union team on 47 occasions, including appearances at the 1999 and 2003 Rugby World Cups. Grau played for in Argentina, Golden Lions in South Africa, US Dax in France, Saracens in England. Starting from 2009, he coached U.R. Cuyo.