This essay examines the growth of symbolic interactionism (SI) as a specialization in English-language Canadian sociology, 1922–1979. We do not focus on theoretical and/or methodological developments. Rather, we document three empirical indicators of the institutionalization of SI: faculty members hired, research published, and SI-receptive programs established. We find that Canadian sociologists institutionalized SI in two phases. From 1922 to 1959, SI institutionalized slowly. There were few SI “core” faculty and scarcely more “SI-accommodative” faculty. Little SI-based literature was published. McGill had Canada’s only SI-friendly program. After 1960, SI grew rapidly and, by 1979, was well institutionalized: over ninety SI and SI-accommodative faculty had been hired, SI literature (journal articles, textbooks) was commonplace. Many sociology departments offered an SI-accommodative program. Sometime in the 1980s, classical SI began to “de-institutionalize.” Ironically, as SI’s footprint grew and influence spread, it appeared to become less discernable, less coherent and less viable as a distinct and unified approach.