- 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 gen/admiral and Huguenot leader, beheaded
- Aug 24 Death of thousands of French Protestants by Roman Catholics in the St. Bartholomew's Day Massacre, beginning in Paris
- 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 27 Claude Goudimel, French composer