October is the tenth month of the Human year.
The gunfight at the OK Corral took place on October 26, 1881 in Tombstone, Arizona. (TOS: "Spectre of the Gun")
On October 4, 1957 the Soviet Union launched Earth's first artificial satellite, Sputnik 1. (ENT: "Carbon Creek")
Vulcans T'Mir and Stron were stranded on Earth in October of 1957 when their ship crash-landed near Carbon Creek, Pennsylvania. (ENT: "Carbon Creek")
Baseball great Buck Bokai was born on October 31st, 1998 in Marina del Rey, California. (DS9: "The Storyteller")
The Ares IV command module, piloted by ISA astronaut Lieutenant John Kelly, disappeared from Mars orbit on October 19, 2032 due to the effects of a graviton ellipse. (VOY: "One Small Step")
John Kelly died on October 29, 2032 after failing a final attempt to escape from the graviton ellipse. (VOY: "One Small Step")
Earth's First Contact with the Coridans occurred in October of 2151. (ENT: "Shadows of P'Jem")
In October of 2153, Hoshi Sato was telepathically contacted by the alien Tarquin while traveling through the Delphic Expanse aboard the Enterprise NX-01. (ENT: "Exile")
Captain Jonathan Archer, Lieutenant Malcolm Reed and MACO Major Hayes of the Enterprise NX-01 visited a Xindi-Arboreal colony in October of 2153. (ENT: "The Shipment")
In an alternate timeline, Captain Archer's brain was infected with interspatial parasites in October of 2153. (ENT: "Twilight")
Earth's first contact with the Skagarans occurred in October of 2153. (ENT: "North Star")
Beverly Howard was born in Copernicus City on Luna on October 13, 2324. (TNG: "Conundrum")
Miles O'Brien married Keiko Ishikawa on the USS Enterprise-D on October 24th, 2367. (TNG: "Data's Day")
Some of the events in the Eugenics Wars novel The Rise and Fall of Khan Noonien Singh, Volume 2 took place on October 1st, 1993 and October 2nd, 1994.
A clipping in Captain Picard's photo album (seen in Star Trek Generations) suggests the Federation Charter was signed on October 11th, 2161. This, however, is not considered canon as the clipping was not visible on-screen.
Many of the events in the novel Articles of the Federation took place in October of 2380.