Peter Albert David Singer (born 6 July 1946) is an Australian philosopher, currently a professor of philosophy at Princeton University and at the University of Melbourne. Singer is generally regarded as one the most influential living philosophers, and has been a key figure behind both the animal welfare and the effective altruism movements.

Singer is the recipient of the 2021 Berggruen Prize, sometimes described as "the Nobel Prize for philosophy". The committee praised Singer for reinvigorating utilitarianism both within academia and as a force in the world (Schuessler 2021). Singer announced he would donate half of the $1 million prize to The Life You Can Save.