Oscar Lewis (born Lefkowitz, December 25, 1914, New York City- died December 16, 1970) was an American anthropologist who is best known for his vivid depictions of the lives of slum dwellers and for postulating that there was a cross-generational culture of poverty among poor people that transcended national boundaries. Lewis contended that the cultural similarities occurred because they were "common adaptations to common problems", and that "the culture of poverty is both an adaptation and a reaction of the poor to their marginal position in a class-stratified, highly individualistic, capitalistic society."
Lewis grew up on a farm in upstate New York. He received a bachelor's degree from City College of New York in history, and a Ph.D. in anthropology from Columbia University, He taught at Brooklyn College, and Washington University, and helped to found the anthropology department at the University of Illinois Urbana-Champaign.