This article offers an analysis of the place held by Acadia in the ideology of priest-historian Lionel Groulx, one of Québec’s most influential nationalist thinkers during the first half of the twentieth century. Acadia always represented a significant conceptual challenge for Groulxist ideology, which defined the French-Canadian nation in traditionalist and providentialist terms, while attempting to consolidate Québec’s “metropolitan” consciousness in its dealings with French minorities, defined in “diasporic” terms, elsewhere in Canada and in North America. However, since Acadia had constructed a specific narrative identity distinct from that of French Canada, Groulx’s efforts in fostering closer ties among all French-language communities had less success there than in other parts of “French America.” Though Groulx readily recognized Acadians’ national distinctiveness, along with the fact that Québec was not their “parent” state in the strictest sense, he was, however, less willing to tolerate that this specificity become an obstacle to the transborder solidarity upon which depended, in his view, “French America”’s temporal and spiritual fate. Through Groulx, this paper thus attempts to better understand the complexity and ambiguity of Québec’s relationship with Acadia prior to the Quiet Revolution of the 1960s.