Sir Arthur Ignatius Conan Doyle DL (22 May 1859 – 7 July 1930) was a Scottish physician and writer, most noted for his stories about the detective Sherlock Holmes, generally considered milestones in the field of crime fiction, and for the adventures of Professor Challenger. He was a prolific writer whose other works include fantasy and science fiction stories, plays, romances, poetry, non-fiction and historical novels.

Arthur Conan Doyle was born on 22 May 1859 at 11 Picardy Place, Edinburgh, Scotland. His father, Charles Altamont Doyle, was English of Irish descent, and his mother, born Mary Foley, was Irish. They married in 1855. In 1864 the family dispersed due to Charles's growing alcoholism and the children were temporarily housed across Edinburgh. In 1867, the family came together again and lived in squalid tenement flats at 3 Sciennes Place.

Supported by wealthy uncles, Conan Doyle was sent to the Roman Catholic Jesuit preparatory school Hodder Place, Stonyhurst, at the age of nine (1868-1870). He then went on to Stonyhurst College until 1875. From 1875 to 1876, he was educated at the Jesuit school Stella Matutina in Feldkirch, Austria.

From 1876 to 1881 he studied medicine at the University of Edinburgh, including a period working in the town of Aston (now a district of Birmingham) and in Sheffield, as well as in Shropshire at Ruyton-XI-Towns. While studying, Conan Doyle began writing short stories. His earliest extant fiction, "The Haunted Grange of Goresthorpe", was unsuccessfully submitted to Blackwood's Magazine. His first published piece "The Mystery of Sasassa Valley", a story set in South Africa, was printed in Chambers's Edinburgh Journal on 6 September 1879. On 20 September 1879, he published his first non-fiction article, "Gelsemium as a Poison" in the British Medical Journal.

Following his studies at university, Conan Doyle was employed as a doctor on the Greenland whaler Hope of Peterhead, in 1880, and, after his graduation, as a ship's surgeon on the SS Mayumba during a voyage to the West African coast, in 1881. He completed his doctorate on the subject of tabes dorsalis in 1885.

In 1882 he joined former classmate George Turnavine Budd as his partner at a medical practice in Plymouth, but their relationship proved difficult, and Conan Doyle soon left to set up an independent practice. Arriving in Portsmouth in June of that year with less than £10 (£700 today) to his name, he set up a medical practice at 1 Bush Villas in Elm Grove, Southsea. The practice was initially not very successful. While waiting for patients, Conan Doyle again began writing stories and composed his first novels, The Mystery of Cloomber, not published until 1888, and the unfinished Narrative of John Smith, which would go unpublished until 2011. He amassed a portfolio of short stories including "The Captain of the Pole-Star" and "J. Habakuk Jephson's Statement", both inspired by Doyle's time at sea.

Portrait of Doyle by Herbert Rose Barraud, 1893

Doyle struggled to find a publisher for his work. His first significant piece, A Study in Scarlet, was taken by Ward Lock & Co on 20 November 1886, giving Doyle £25 for all rights to the story. The piece appeared later that year in the Beeton's Christmas Annual and received good reviews in The Scotsman and the Glasgow Herald. The story featured the first appearance of Watson and Sherlock Holmes, partially modelled after his former university teacher Joseph Bell. Conan Doyle wrote to him, "It is most certainly to you that I owe Sherlock Holmes... [R]ound the centre of deduction and inference and observation which I have heard you inculcate I have tried to build up a man." Robert Louis Stevenson was able, even in faraway Samoa, to recognise the strong similarity between Joseph Bell and Sherlock Holmes: "[M]y compliments on your very ingenious and very interesting adventures of Sherlock Holmes. ... [C]an this be my old friend Joe Bell?" Other authors sometimes suggest additional influences—for instance, the famous Edgar Allan Poe character C. Auguste Dupin.

A sequel to A Study in Scarlet was commissioned and The Sign of the Four appeared in Lippincott's Magazine in February 1890, under agreement with the Ward Lock company. Doyle felt grievously exploited by Ward Lock as an author new to the publishing world and he left them. Short stories featuring Sherlock Holmes were published in the Strand Magazine. Sir Arthur Conan Doyle first began to write for the ‘Strand’ from his home at 2 Upper Wimpole Street, now marked by a memorial plaque.

Conan Doyle was found clutching his chest in the hall of Windlesham Manor, his house in Crowborough, East Sussex, on 7 July 1930. He died of a heart attack at the age of 71. His last words were directed toward his wife: "You are wonderful." At the time of his death, there was some controversy concerning his burial place, as he was avowedly not a Christian, considering himself a Spiritualist. He was first buried on 11 July 1930 in Windlesham rose garden. He was later reinterred together with his wife in Minstead churchyard in the New Forest, Hampshire. Carved wooden tablets to his memory and to the memory of his wife are held privately and are inaccessible to the public. That inscription reads, "Blade straight / Steel true / Arthur Conan Doyle / Born May 22nd 1859 / Passed On 7th July 1930." The epitaph on his gravestone in the churchyard reads, in part: "Steel true/Blade straight/Arthur Conan Doyle/Knight/Patriot, Physician, and man of letters".