Arthur Conan Doyle was born the third of ten siblings on 22 May 1859 in Edinburgh, Scotland. His father, Charles Altamont Doyle, was born in England of Irish descent, and his mother, born Mary Foley, was Irish. They were married in 1855.

Although he is now referred to as Conan Doyle, the origin of this compound surname (if that is how he meant it to be understood) is uncertain. His baptism record in the registry of St Marys Cathedral in Edinburgh gives Arthur Ignatius Conan as his Christian name, and simply Doyle as his surname. It also names Michael Conan as his godfather.
At the age of nine Conan Doyle was sent to the Roman Catholic Jesuit preparatory school, Hodder Place, Stonyhurst. He then went on to Stonyhurst College, leaving in 1875.
From 1876 to 1881 he studied medicine at the University of Edinburgh. This required that he provide periodic medical assistance in the towns of Aston (now a district of Birmingham) and Sheffield. While studying, Conan Doyle began writing short stories. His first published story appeared in Chamberss Edinburgh Journal before he was 20. Following his graduation, he was employed as a ships doctor on the SS Mayumba during a voyage to the West African coast. He completed his doctorate on the subject of tabes dorsalis in 1885.
In 1885 Conan Doyle married Louisa (or Louise) Hawkins, known as Touie. She suffered from tuberculosis and died on 4 July 1906. The following year he married Jean Elizabeth Leckie, whom he had first met and fallen in love with in 1897. Due to his sense of loyalty he had maintained a purely platonic relationship with Jean while his first wife was alive. Jean died in London on 27 June 1940.

Conan Doyle fathered five children. Two with his first wife Mary Louise (28 January 1889 - 12 June 1976), and Arthur Alleyne Kingsley, known as Kingsley (15 November 1892 - 28 October 1918). With his second wife he had three children Denis Percy Stewart (17 March 1909 - 9 March 1955).