This critical review examines the past 15 years of scholarship about contextual influences in TP(A)CK to better understand its theoretical bases. While Bronfenbrenner’s ecological systems theory is usually applied in this work, either implicitly or explicitly, its articulation is most often incomplete and/or inaccurate, with some confusion evident about the nature and foci of multiple, intersecting systems of contextual influences. We argue for a more comprehensive way to theorize context in future TP(A)CK research, using Bronfenbrenner’s systemic explanations of the complex and interdependent aspects of contextual influences and actors. We also recommend additional focus upon indirect, intersectional and sociocultural influences upon teachers’ TP(A)CK-based knowledge and action.