Singer, Peter (1946-) is an Australian animal rights activist and philosopher who is credited with inspiring the modern animal rights movement. This movement is an organized effort opposing the use of animals for research, food, and clothing. Animal rights activists believe that animals feel pain and have reasoning ability and should receive greater moral consideration from human beings than human beings generally give them. Singer rejects any form of cruelty to animals.

Peter Albert David Singer was born July 6, 1946, in Melbourne, Australia. His parents, Ernst Singer and Cora Renata Oppenheim Singer, were Austrian Jewish refugees who fled after Adolf Hitler invaded Austria. Ernst Singer had worked in the tea and coffee importing business, and Cora Singer was a doctor. Three of Singer's grandparents died in the Holocaust.

Singer attended the University of Melbourne and received a B.A. degree with honors in 1967 and an M.A. degree in philosophy in 1969. He went on to study at the University of Oxford, in England, earning a B.Phil. degree in 1971.

He taught at Oxford, New York University, and La Trobe University in Bundoora, Melbourne. In 1977, he became a professor of philosophy at Monash University in suburban Melbourne. He became professor of bioethics at Princeton University in 1999. Singer coedits the journal Bioethics .

Singer's Animal Liberation (1975) established the modern animal rights movement. Singer used the term speciesism, relating it to racism and sexism, to mean the dominance of “human over nonhuman animals.” He compared the movement for ethical treatment of animals to the liberation movements of women and blacks. He used philosophical arguments to counter the Biblical concept of man's dominion over animals.

His Practical Ethics (1979) became a widely used textbook in applied ethics. Singer wrote, co-wrote, or edited many articles and over 25 books.

Since the 1970's, the animal rights movement has expanded at a dramatic rate worldwide. People for the Ethical Treatment of Animals and the Humane Society of the United States are leading animal protection organizations.