- Aug 12 William Jackson Hooker, English botanist and director (Kew Gardens), dies at 80
- Aug 13 Ignaz Semmelweis, Hungarian physician who discovered the cause of puerperal (childbed) fever and introduced antisepsis into medical practice, dies at 47
- Aug 17 Johann Nepomuk Poissl, Bavarian composer, dies at 82
- Aug 17 Mosby Munroe Parsons, United States officer in the Mexican–American War and brigadier general of the Confederate States Army, dies in battle at 42
- Aug 26 Johann Franz Encke, German astronomer (Comet Encke), dies at 73
- Aug 26 Marcellus Monroe Crocker, US attorney/Union brigadier general, dies at 35
- Aug 27 Józef Nowakowski, Polish pianist and composer, dies at 64
- Aug 27 Thomas Chandler Haliburton, Canadian novelist (The Clockmaker; or, The Sayings and Doings of Samuel Slick of Slickville), dies at 68
- Aug 29 John Brough, US publisher/(gov-R-Ohio), dies at about 54
Assassination
Drug Overdose
Gunshot Wound
Murder
Plane Crash
Suicide