- Mar 1 Richard Zouch, English jurist, dies at 71
- Mar 8 Jules Mazarin, Italian cardinal/premier of France, dies at 58
- Mar 9 Jules "Cardinal" Mazarin, chief minister of France, dies at 58
- Mar 22 Hendrick Uylenburgh, Dutch art dealer who launched Rembrandt and others, buried at about 73
- Mar 24 William Leddra becomes the last Quaker to be hanged in Boston, for the crime of returning from banishment