William Petersen (August 3, 1912 – June 10, 2004) was an American sociologist and demographer.
He taught in the Sociology Department at the University of California at Berkeley from 1953 to 1956 and 1959 to 1966.
He created the term "model minority" to describe his thesis that Japanese American success posed challenges to simple discrimination-based accounts of group socioeconomic differences.
From 1966 to 1967, Petersen was professor of sociology at Boston College, and from 1967 to 1978 he was the Robert Lazarus Professor of Social Demography at Ohio State University.
He co-authored Dictionary of Demography: Biographies with his wife, Rene, in 1985.