Guy Newell Boothby (13 October 1867 – 26 February 1905) was an Australian novelist and writer.
Boothby was born in Adelaide, son of Thomas Wilde Boothby, who for a time was a member of the South Australian Legislative Assembly. Guy Boothby's grandfather was Benjamin Boothby (1803-1868), judge of the supreme court of South Australia from 1853 to 1867. When Boothby was six he travelled to England with his mother, and thus was educated at Salisbury, Lord Weymouth's Grammar (now Warminster School) and Christ's Hospital, London.
In 1890 Boothby wrote the libretto for a comic opera, Sylvia, which was published and produced at Adelaide in December 1890, and in 1891 appeared The Jonquil: an Opera. The music in each case was written by Cecil James Sharp. Around this time Boothby accepted a role as private secretary to the mayor of Adelaide, Lewis Cohen, but was "not contented" with the work. There was little opportunity for Boothby to progress in the Adelaide Corporation: thus, with the support of Cohen, Boothby moved to Brisbane where he believed that he would find "a wider opening for his talents". From Brisbane Boothby made his way to England, arriving in London in 1894.
In 1894 he published On the Wallaby or Through the East and Across Australia, an account of the travels of himself and his brother, including a description of their journey across Australia from Cooktown to Adelaide. In the same year his first novel, In Strange Company, was published in London and was quickly successful. Boothby moved to the United Kingdom in 1894. He wrote over 50 books over the course of a decade, before dying of pneumonia in Bournemouth.
Some of Boothby's earlier works relate to stories of Australian life, but later he turned to genre fiction. He was once well known for his series of five novels about Doctor Nikola, an occultist anti-hero seeking immortality and world domination. In A Prince of Swindlers he created the character of Simon Carne, a gentleman thief in the Raffles mould, with an alter ago as the eccentric detective Klimo: Carne first appeared in Pearson's Magazine in 1897, predating Raffles by two years.
Doctor Nikola 
- A Bid for Fortune: or, Dr Nikola's Vendetta (1895) (AKA Enter, Dr Nikola)
- Dr Nikola (1896) also as Dr. Nikola Returns
- The Lust of Hate (1898)
- Dr Nikola's Experiment (1899)
- "Farewell, Nikola" (1901)
Other works 
Other books written by Guy Boothby include:
- On the Wallaby: or, Through the East and Across Australia (1894)
- A Lost Endeavour (1895)
- The Marriage of Esther: a Torres Straits Sketch (1895)
- In Strange Company: a Story of Chili and the Southern Seas (1896)
- The Beautiful White Devil (1897)
- Bushigrams (1897)
- The Fascination of the King (1897)
- The Phantom Stockman (1897)
- Sheila McLeod: a Heroine of the Back Blocks (1897)
- The Duchess of Wiltshire's Diamonds (1897)
- Across The World For a Wife (1898)
- Billy Binks, Hero: and Other Stories (1898)
- Love Made Manifest (1899)
- Pharos, The Egyptian (1899)
- The Red Rat's Daughter (1899)
- A Sailor's Bride (1899)
- "Long Live the King!" (1900)
- A Maker of Nations (1900)
- A Prince of Swindlers (1900) (AKA The Viceroy's Protegé)
- The Woman of Death (1900)
- The Boundary Rider: a Play in One Act (1901)
- A Cabinet Secret (1901)
- The Jonquil (1901)
- A Millionaire's Love Story (1901)
- My Indian Queen: Being a Record of Sir Charles Verrinder, Baronet, in the East Indies (1901)
- The Mystery of the Clasped Hands (1901)
- The Rickshaw: a Farce in Two Acts (1901)
- My Strangest Case (1901)
- The Childerbridge Mystery (1902)
- The Curse of the Snake (1902)
- The Kidnapped President (1902)
- Uncle Joe's Legacy: and Other Stories (1902)
- Connie Burt (1903)
- The Countess Londa (1903)
- The League of Twelve (1903)
- A Queer Affair (1903)
- A Two-fold Inheritance (1903)
- A Bid for Freedom (1904)
- A Bride from the Sea (1904)
- A Consummate Scoundrel (1904)
- A Desperate Conspiracy (1904)
- The Lady of the Island (1904) ("A Professor of Egyptology", "The Black Lady of Brin Tor", "A Strange Goldfield")
- An Ocean Secret (1904)
- A Brighton Tragedy (1905)
- A Crime of the Under-seas (1905)
- For Love of Her (1905)
- In Spite of the Czar (1905)
- A Lost Endeavor (1905)
- The Race of Life (1906)
- A Royal Affair: and Other Stories (1906)
- A Stolen Peer (1906)
- The Man of the Crag (1907)
- In the Power of the Sultan (1908)
See also 
- 'Boothby, Guy Newell (1867-1905)', Australian Dictionary of Biography, Volume 7, Melbourne University Press, 1979, pp 347-348.
- G. N. Hawker, 'Boothby, Thomas Wilde (1839-1885)', Australian Dictionary of Biography, Volume 3, Melbourne University Press, 1969, pp 196-197.
- Alex C Castles, 'Boothby, Benjamin (1803-1868)', Australian Dictionary of Biography, Volume 3, Melbourne University Press, 1969, pp 194-196.
- Zampieri, Emilio (2010). Guy Boothby : the Dr. Nikola novels (1895-1901) (PhD thesis). Università degli Studi di Padova. OCLC 664681561. http://paduaresearch.cab.unipd.it/2765/12/merged.pdf. Retrieved 7 July 2011.
- "Obituary: Mr. Guy Boothby". The Advertiser. 1 March 1905.
- Bulfin, Ailise. "Guy Boothby". The Irish Journal of Gothic and Horror Studies. Retrieved 7 July 2011.
- Serle, Percival (1949). "Boothby, Guy". Dictionary of Australian Biography. Sydney: Angus and Robertson.
- Works by Guy Boothby at Project Gutenberg
- ebooks of works by Guy Boothby at Project Gutenberg Australia
- Guy Boothby at the Internet Speculative Fiction Database
- Emilio Zampieri: Guy Boothby: The "Dr. Nikola" Novels. (Dissertation, Universita degli studi di Padova, online)