|Centuries:||16th century – 17th century – 18th century|
|Decades:||1580s 1590s 1600s – 1610s – 1620s 1630s 1640s|
|Years:||1615 1616 1617 – 1618 – 1619 1620 1621|
- March 8 – Johannes Kepler discovers the third law of planetary motion (he soon rejects the idea after some initial calculations were made but on May 15 confirms the discovery).
- May 23 – The Second Defenestration of Prague – Protestant noblemen throw three representatives of Ferdinand II out of a window. The event began the Thirty Years' War.
- July 20 – Pluto reached, according to sophisticated mathematical calculations, its second most recent aphelion. The next one occurred in 1866, and the following one will occur in 2113.
- August 29 – Johan van Oldenbarnevelt and Hugo Grotius are imprisoned by Maurice of Nassau, Prince of Orange
- October 29 – English adventurer, writer, and courtier Sir Walter Raleigh is beheaded for allegedly conspiring against James I of England.
- The margraves of Brandenburg is granted Polish approval to inherit Ducal Prussia.
- November 13, the Synod of Dordrecht has its first meeting.
- Change of emperor of the Ottoman Empire from Mustafa I (1617-1623) to Osman II (1618-1622).
- The 3000 seat Teatro Farnese, the first permanent proscenium theatre, was built into the Great Hall of the Palazzo della Pilotta in Parma, Italy in 1618.