Mario L. Small has made numerous contributions to research on urban neighborhoods, personal networks, qualitative and mixed methods, and other topics. Small's most recent book examines why people are consistently willing to confide their deepest worries to people they are not close to, and proposes an approach to network analysis that begins with what people do in practice.  

Small, the only two-time recipient of the C. Wright Mills Best Book Award, has received numerous awards for each of his books, including the Robert Park Best Book Award, the James Coleman Best Book Award, a PROSE Award Honorable Mention in Sociology and Anthropology, a Choice Outstanding Academic Title designation, and many others.  His articles have been published in the Proceedings of the National Academy of Science, American Journal of Sociology, Theory and Society, Social Networks, Annual Review of Sociology, Social Forces, and Social Science Research, among other journals; his work has been featured by the New York Times, the Washington Post, Public Radio International, the Huffington Post, Pacific Standard, Greater Good, the Chronicle Review, Commonwealth, and Spotlight on Poverty, among other outlets.

Small has served as Associate Editor of the American Journal of Sociology, Advisory Editor of Social Problems and Sociological Quarterly, Editorial Committee Member of the Annual Review of Sociology, and Editorial Board Member of Social Psychology Quarterly and Sociological Forum. He is currently Deputy Editor of Sociological Science and Editorial Board Member of Social Science Quarterly. He has served as Council Member of the American Sociological Association, and chaired the ASA’s report on the 2010 National Research Council Assessment of Doctoral Programs. He is an Elected Member of the Sociological Research Association.

At the University of Chicago, as Dean of the Division of the Social Sciences, Small spearheaded initiatives that increased support for students, generated new resources for faculty research, seeded programs in urban and in computational social science, empirically assessed the institutional climate for students and for faculty of all backgrounds, and substantially expanded the Division’s reserves.

He has been a trustee of the National Opinion Research Center and the University of Chicago Charter School, and a board member of the Spencer Foundation. He is currently on the board of the Russell Sage Foundation. Small has advised practitioners and policy makers in the private sector, in the administrations of several major cities, and in the U.S. Congress; served as expert panelist to the Office of the Assistant Secretary of Planning and Evaluation (U.S. Dept. of Health and Human Services); and testified on social capital and inequality before the U.S. Senate. 

Born and raised in Cerro Viento, PTY, Small received a B.A. in 1996 from Carleton College, and an M.A. in 1998 and a Ph.D. in 2001 from Harvard University.