Pavel Andreievich Chekov was a child prodigy and a Starfleet ensign for the Federation, assigned as a navigator to the USS Enterprise in 2258, at the age of 17. In addition, he was able to calculate the coordinates for beaming much faster than the computer, allowing him to personally beam Kirk and Sulu back aboard the Enterprise before they fell into the singularity, when the computer couldn't even lock on to them.
Originating from Russia, he spoke with a heavy Eastern European accent, which caused a problem when he had to voice input his authorization code "9-5-Victor-Victor-2". (His accent meant he had trouble correctly pronouncing Vs, which sounded like W's when he spoke them, hence "9-5-Wiktor-Wiktor-2.")
Chekov displayed great intellectual brilliance when he was able to transport James T. Kirk and Hikaru Sulu back to the Enterprise as they were falling to Vulcan. Sadly, he did not have enough time to use the same technique to save Amanda Grayson, Spock's mother.
After the destruction of Vulcan, Chekov devised a way to beam Kirk and Commander Spock to the Narada, without Nero noticing the Enterprise being near his ship. Chekov's plan had the Enterprise drop out of warp near Titan, one of Saturn's moons, which hid the Enterprise from being detected, then had Montgomery Scott beam the two to the Narada. Chekov's plan was ultimately instrumental in saving Earth. After Earth was saved, Chekov served again as navigator under newly promoted Captain James T. Kirk and left with the crew to explore space. (Star Trek)
The following year, Chekov became chief engineering officer after Scott left following a dispute with Kirk, though he expressed some apprehension about donning a red shirt. Chekov had to deal with the warp core breaking down, though it was sufficiently repaired to flee when the Enterprise was attacked by the USS Vengeance. He later prevented Kirk and Scott (who had returned to the ship) from falling to their deaths while the ship lost its artificial gravity.
Chekov attended a memorial for those who died almost a year later, and resumed his role as navigator on the repaired Enterprise when it embarked on the first five-year mission. (Star Trek Into Darkness)
"Russian wizkid, what's your name? Chanko? Cherpov?"
"Ensign Chekov, Pavel Andreievich, sir."
"Fine, Chekov, Pavel Andreievich, begin ship-wide mission broadcast."
"Aye, sir. Happy to."
- - Christopher Pike and Pavel Chekov
"Ensign authorization code Nine-Five-Wictor-Wictor-Two."
"Authorization not recognized."
"Ensign authorization code Nine-Five... Victor... Victor-Two."
- - Pavel Chekov, accessing the ship's all-call system and the Enterprise computer
"ё моё!" (Russian exclamatory expression pronounced as "Yo moyo!" meaning "Oh man!" )
- - Pavel Chekov, after successfully transporting a plummeting Kirk and Sulu from Vulcan's atmosphere
"How old are you?"
"Oh good, he's seventeen."
"Doctor, Mr. Chekov is correct."
- - Leonard McCoy, Pavel Chekov, and Spock, about Chekov's plan to beam aboard the Narada
"Keptin on ze bridge!"
- - Multiple times
Pavel Chekov (alternate reality) appears in:
According to the Star Trek iTunes movie app, Chekov was born in Tagnarog, Russia. His mother's name was Anna (who is now deceased). His family spent several years at the Mare Imbrium colony on Luna. He graduated from Moscow State University in 2256, where he then enlisted in Starfleet. He graduated from Starfleet Academy in 2258. It should be noted that he beat Big Blue in a game of 3D chess. Chekov received a special commendation for bravery in the line of duty during Enterprises recent mission to Pollux IV.