The article examines parallels in canonical function between Deuteronomy and John. Following clarification of the significance of «canonical function», the essay investigates first external parallels between the two books that impact their reading especially within their sections of the OT and NT. It then looks at internal components of the books that contribute to their larger canonical role, with especial attention paid to the role of the future community as implied readership, rhetorical devices, location, and claims of final authority and sufficiency. The article concludes with a proposal regarding ways in which the two books do, indeed, function within their testamental canons in like ways.