Sudhir Alladi Venkatesh is an American sociologist and urban ethnographer. He is William B. Ransford Professor of Sociology & African-American Studies at Columbia University, a position he has held since 1999. In his work, Venkatesh has studied gangs and underground economies, public housing, advertising and technology. As of 2018, he is the Director of Signal: The Tech & Society Lab at Columbia University.

Ethnography is a branch of anthropology and the systematic study of individual cultures. Ethnography explores cultural phenomena from the point of view of the subject of the study. Ethnography is also a type of social research that involves examining the behavior of the participants in a given social situation and understanding the group members' own interpretation of such behavior.