Robert Barr or Bob Barr may refer to:
Robert Barr (Australian politician) (1862–1947)
Robert Barr (field hockey) (born 1978), Scottish field hockey player
Robert Barr (schoolteacher) (1831–1897), English schoolteacher on Vancouver Island
Robert Barr (writer) (1850–1912), British-Canadian novelist
Robert Barr, founder of soft drink manufacturer A.G. Barr
Robert M. Barr (1918–1988), American conductor of Jordan High School Band
Bob Barr (1880s pitcher) (Robert M. Barr, 1856–1930), Major League Baseball pitcher
Bob Barr (1930s pitcher) (Robert A. Barr, 1908–2002), baseball pitcher for the Brooklyn Dodgers
Bob Barr (footballer) (1865–1935), Scottish footballer
Bob Barr (Australian footballer) (born 1945), Australian footballer
Bob Barr (Robert L. Barr, Jr., born 1948) is an American attorney and 2008 Libertarian Party candidate for President of the United States.