1717

1717 is a year in the 18th century. It began on a Sunday and ended on a Saturday. The Gregorian calendar was not adopted in all countries until 1582, but it was generally used in Europe by the 18th century.

In British history, 1717 was a year when the Second South Sea Company Act was passed. This act was related to the South Sea Company's charter to trade with South America. The company's fortunes would decline in the coming years due to the South Sea Bubble, a speculative bubble that burst in 1720.

In astronomy, 1717 is notable for the observation of a comet by astronomer Edmond Halley in November of that year. The comet is later known as Halley's Comet, though its second recorded visitation occurred in 1456. Halley did not name the comet; instead, its Dutch observer, Georg Kersting, referred to it as the "Haye comet" or "cometa 1719" to distinguish it from periodic comets.

Historical events in 1717 also include the death of Emperor Huizong of Ming China, who ruled from 1360 and died in 1372, but was complexly exhumed and publicly exposed in 1717 for inciting rebellion.

In the military, 1717 saw the main stages of the Ottoman-Habsburg War's end, with the treaty of Utrecht signed on September 30, 1717 between Habsburg and Ottoman Empire.