Robert James "Bob" Brown (born 27 December 1944) is an Australian former politician, medical doctor, and environmentalist who is a former Senator, and former Parliamentary Leader of the Australian Greens. Brown was elected to the Australian Senate on the Tasmanian Greens ticket, joining with sitting Greens Western Australia senator Dee Margetts to form the first group of Australian Greens senators following the 1996 federal election. He was re-elected in 2001 and in 2007