| Ronald Adair |
|Died||30 March, 1894|
|Family|| Earl of Maynooth (father)|
Lady Maynooth (mother)
Hilda Adair (sister)
|Behind the scenes|
|Appearances||"The Adventure of the Empty House"|
The Honourable Ronald Adair was a British noble. He was the second son of the Earl of Maynooth, governor of an Australian colony. His murder at his Park Lane home in 1894 shocked London's fashionable society and confounded the police, who only managed to solve the case after the reappearance of Sherlock Holmes. The crime was found to be the work of Colonel Sebastian Moran, the former second-in-command of Professor James Moriarty. Moran killed Adair because the younger man was his whist partner in the clubs, and was about to expose how the Colonel's cheating had enriched them both by returning his share of the ill-gotten gains to the men Moran had swindled.
- All of the above took place before the story began in "The Adventure of the Empty House", wherein Colonel Moran was arrested for this murder.