William Shaffir is a Canadian sociologist. Shaffir has conducted studies on Canadian Jews, particularly on Hasidic Jews in Canada. He is the Associate Chair of the Sociology Department at McMaster University. He co-authored the book The Jews in Canada.

William Shaffir has conducted a number of qualitative studies on Canadian Jewry.

Shaffir has conducted studies on several of the Hasidic groups in Montreal, including the Chabad-Lubavitch and Tosh Hasidic communities.