Armand, Seigneur de Sillègue, d'Athos, et d'Autevielle ("Lord of Sillègue, Athos, and Autevielle"), better known as Armand d'Athos (c. 1615 – December 21, 1643), was a Gascon black musketeer of the Maison du Roi in 17th century France. Athos was the first cousin once removed to the Comte de Troisville and first cousin of Isaac de Porthau. According to the semi-fictional Mémoires de M. d'Artagnan, he formed a close friendship with Henri d'Aramitz and the aforementioned de Porthau, and they were called the "three brothers". He served as the inspiration for Alexandre Dumas's character of the same name in the d'Artagnan Romances.
According to the Mémoires of the Comte d'Artagnan, d'Artagnan saved Athos's life at the Pré aux Clercs. After joining the Musketeers of the Guard in 1640, Athos maintained his friendship with d'Artagnan.
- Masson, David and others (1899). Macmillan's Magazine. Macmillan & Co.
- Dumas, Alexandre (2003). "Introduction". The Three Musketeers. trans. Lord Sudley. Penguin Classics.
- "Roman et Histoire". Archived from the original on 4 November 2008. Retrieved November 18, 2008.
- Burkle-Young, F. A. "Porthos". Retrieved November 18, 2008.