Peter Albert David Singer (born 6 July 1946) is an Australian moral philosopher and the Ira W. DeCamp Professor of Bioethics at Princeton University. He specialises in applied ethics, approaching the subject from a secular, utilitarian perspective. He wrote the book Animal Liberation (1975), in which he argues for veganism, and the essay "Famine, Affluence, and Morality", which favours donating to help the global poor. For most of his career, he was a preference utilitarian, but he revealed in The Point of View of the Universe (2014), coauthored with Katarzyna de Lazari-Radek, that he had become a hedonistic utilitarian.

On two occasions, Singer served as chair of the philosophy department at Monash University, where he founded its Centre for Human Bioethics. In 1996 he stood unsuccessfully as a Greens candidate for the Australian Senate. In 2004 Singer was recognized as the Australian Humanist of the Year by the Council of Australian Humanist Societies. In 2005, The Sydney Morning Herald placed him among Australia's ten most influential public intellectuals. Singer is a cofounder of Animals Australia and the founder of The Life You Can Save.⁠

Peter Singer