Thomas Edison was born, in 1847, in Milan, Ohio, and grew up in Port Huron, Michigan. He was the seventh and last child of Samuel Ogden Edison Jr. (1804–1896, born in Marshalltown, Nova Scotia) and Nancy Matthews Elliott (1810–1871, born in Chenango County, New York). His father, the son of a Loyalist refugee, had moved as a boy with the family from Nova Scotia, settling in southwestern Ontario (then called Upper Canada), in a village known as Shrewsbury, later Vienna, by 1811. Samuel Jr. eventually fled Ontario, because he took part in the unsuccessful Mackenzie Rebellion of 1837. His father, Samuel Sr., had earlier fought in the War of 1812 as captain of the First Middlesex Regiment. By contrast, Samuel Jr.'s struggle found him on the losing side, and he crossed into the United States at Sarnia-Port Huron. Once across the border, he found his way to Milan, Ohio. His patrilineal family line was Dutch by way of New Jersey; the surname had originally been "Edeson."
Edison attended school for only a few months, and was instead taught by his mother. Much of his education came from reading R.G. Parker's School of Natural Philosophy and The Cooper Union for the Advancement of Science and Art.
Edison developed hearing problems at an early age. The cause of his deafness has been attributed to a bout of scarlet fever during childhood and recurring untreated middle-ear infections. Around the middle of his career, Edison attributed the hearing impairment to being struck on the ears by a train conductor when his chemical laboratory in a boxcar caught fire and he was thrown off the train in Smiths Creek, Michigan, along with his apparatus and chemicals. In his later years, he modified the story to say the injury occurred when the conductor, in helping him onto a moving train, lifted him by the ears.