Rachel Siewert was a Federal Senate Member of Western Australia for the Australian Greens. She was prominently involved in the establishment and running of the Conservation Council of Western Australia, working for a number of years as its coordinator, and was awarded the Bessie Rischbieth Conservation Award in 2003.
Ms Siewert was a senator for Western Australia from 2005 to 2021, a co-convener of The Greens (WA) from 2002 to 2004 and the party's co-deputy leader from 2017 to 2018.