David William Goodall was an English-born Australian botanist and ecologist. He was influential in the early development of statistical methods in plant communities. He worked as researcher and professor in England, Australia, Ghana and the United States. He was editor-in-chief of the 30-volume Ecosystems of the World series of books, and author of over 100 publications. Still active past the age of 100, he was known as Australia's oldest working scientist. An advocate of voluntary euthanasia legalisation, he ended his own life in Switzerland via physician-assisted suicide at the age of 104.