Mark Sanford Granovetter (/ ˈɡrænəvɛtər /; born October 20, 1943) is an American sociologist and professor at Stanford University. He is best known for his work in social network theory and in economic sociology, particularly his theory on the spread of information in social networks known as The Strength of Weak Ties (1973).

In The Development of Social Network Analysis, Linton C. Freeman, of UC Irvine, writes that Dr. Jacob Levy Moreno is the pioneer of SNA as we know it today, arguing on the basis of his work in the 1930s. There had been previous attempts to incorporate the abstractions of nodes and links to the study of human structures.