Dix was born on April 4, 1802, in Hampden, Maine. Her father, Joseph Dix, was an alcoholic and circuit-riding Methodist preacher who required young Dorothea to spend her time laboriously stitching and pasting the thick religious tracts he wrote and sold during his travels. Although considered a strict and sometimes abusive father, Joseph Dix taught his daughter to read and write at an early age. Dix, in turn, taught reading and writing to her two younger brothers. Her mother, Mary (Bigelow) Dix, suffered from depression that made it difficult for her to care for her three children.