Ernest Thompson Seton was born on August 14, 1860 in South Shields, England. Seton's family emigrated to Canada in 1866. Most of his childhood was spent in Toronto, Ontario. As a youth, he retreated to the woods to draw and study animals as a way of avoiding his abusive father. On his twenty-first birthday, Seton's father presented him with an invoice for all the expenses connected with his childhood and youth, including the fee charged by the doctor who delivered him. He paid the bill, but never spoke to his father again.
At the age of 21 he took the surname Seton in the belief that his father was the true heir to the lands and titles of Lord Seton, Earl of Winton.
After an appeal from his mother in 1887, he resumed the Thompson surname and began using the nom de plume Ernest Seton-Thompson on his published works; in 1901 he changed his name legally to Ernest Thompson Seton.