Acadia (in the French language Acadie) was a colony of New France, in northeastern North America that included parts of eastern Quebec, the Maritime provinces, and modern-day Maine to the Kennebec River. During much of the 17th and early 18th centuries, Norridgewock on the Kennebec River and Castine at the end of the Penobscot River were the southern-most settlements of Acadia. The actual specification by the French government for the territory refers to lands bordering the Atlantic coast, roughly between the 40th and 46th parallels. Later, the territory was divided into the British colonies which became Canadian provinces and American states. The population of Acadia included descendants of emigrants from France (i.e., Acadians) along with those from the Wabanaki Confederacy. The two communities inter-married, which resulted in a significant portion of the population of Acadia being Métis.

The Association for Computer Aided Design In Architecture (ACADIA) is a non-profit organization active in the area of computer-aided architectural design (CAAD).