- Aug 20 Miguel López de Legazpi, Spanish conquistador (b. 1502)
- Aug 22 Thomas Percy, 7th Earl of Northumberland (b. 1528)
- Aug 24 Gaspard de Châtillon, Count the Coligny, French admiral and Huguenot leader, who death ignited the St. Bartholomew's Day Massacre, beheaded at 53
- Aug 24 Pierre de la Ramée, French humanist (b. 1515)
- Aug 24 Charles de Téligny, French Huguenot soldier, one of the 1st murdered during St. Bartholomew's day massacre, dies at about 37
- Aug 26 Petrus Ramus, French philosopher (b. 1515)
- Aug 29 Claude Goudimel, French composer, music theorist, music editor and publisher, dies between 52 and 58 [birthdate disputed]