Famous birthdays, deaths and events of 1655
- January 6 - Eleonore-Magdalena of Neuburg, Holy Roman Empire Empress (d. 1720)
- May 4 - Bartolomeo Cristofori, Italian maker of musical instruments (d. 1731)
- November 24 - Charles XI of Sweden, (d. 1697)
- December 28 - Charles Cornwallis, 3rd Baron Cornwallis
- July 28 - Cyrano de Bergerac, French poet (b. 1619)
- August 10 - Alfonso de la Cueva, marqués de Bedmar
- March 25 - Saturn's largest moon, Titan, is discovered by Christian Huygens.
- April 4 - The miraculous statue entitled the Infant of Prague is solemnly crowned by command of Cardinal Harrach.
- May 10 - England, with troops under the command of Admiral William Penn and General Robert Venables, annexes Jamaica from Spain.
- July 31 - Russo-Polish War (1654-1667): the Russian army enters the capital of the Grand Duchy of Lithuania, Vilnius, which it holds for six years.
- August 29 - Warsaw falls without resistance to a small force under the command of Charles X Gustav of Sweden during The Deluge.