Cyr Plantation was first settled by Acadian exiles in the 1820s, and was first organized for election purposes in 1857, although its formal organization as a plantation was confirmed on March 12, 1870. The plantation was named for the numerous Cyrs who settled the area.
Cyr Plantation is located in the northeastern portion of Aroostook County, about seventy miles north of Houlton. Nearby towns are Hamlin, to the east; and Van Buren to the north. Hammond Brook and Violette Brook form the northern and eastern boundaries of the town respectively, while Railway Brook, running south to drain into Little Madawaska Brook, forms its western boundary.