1859 ( MDCCCLIX) was a common year starting on Saturday of the Gregorian calendar and a common year starting on Thursday of the Julian calendar, the 1859th year of the Common Era (CE) and Anno Domini (AD) designations, the 859th year of the 2nd millennium, the 59th year of the 19th century, and the 10th and last year of the 1850s decade.

August 28 – September 2 – The solar storm of 1859, the largest geomagnetic solar storm on record, causes the Northern lights to be visible as far south as Montería, Colombia and knocks out telegraph communication (this is also called the Carrington Event). September – British merchant Thomas Blake Glover begins business in Nagasaki, Japan.

A solar flare associated with the geomagnetic storm was observed and recorded independently by British astronomers Richard Carrington and Richard Hodgson on 1 September 1859. A geomagnetic storm of this magnitude occurring today would cause widespread electrical disruptions, blackouts, and damage due to extended outages of the electrical grid.

"The grand aurorae borealis seen in Colombia in 1859". Advances in Space Research. 57 (1): 257–267. arXiv: 1508.06365. Bibcode: 2016AdSpR..57..257M. doi: 10.1016/j.asr.2015.08.026.