Montgomery Scott (referred to as Scotty by his shipmates), serial no. SE 19754 T, was the chief engineer of both the USS Enterprise and the USS Enterprise-A for a period of nearly thirty years as well as a very short period with the Excelsior.

Born in Aberdeen,Scotland on Earth in 2222. He joined Starfleet and began his engineering career in 2241. During his 52-year career in Starfleet, he served on a total of eleven ships, including vaious freighters, cruisers and starships.

Scott was the first to postulate the theory of transwarp beaming.

In 2265, Scott was assigned to the USS Enterprise where he served as second officer and chief engineer under Captain James T.Kirk.

His duties also included maintenance and operation of the Enterprise's transporter systems. Three of his top engineers included Lieutenants Kyle, Leslie and Gabler.

As the ship's second officer, Scott assumed command when both Kirk and Spock left the ship, or they both were incapacitated. Thus, he often faced critical diplomatic and military situations.

In 2268 Kirk noted him to commendation for his outstanding command performance without disobeying the Prime Directive and saving the landing party on planet 892-IV.

However in 2267, Kirk jokingly "fired" Scott when he couldn't repair the ship's engines and break out of orbit around Gamma Trianguli VI. After the destruction of Vaal Kirk immediately "re-hired" him.

By the late 2260s, Scott knew more about the warp engines aboard a Constitution-class starship than the men who designed them. This knowledge and ability to save the ship in a jam eventually led to his reputation aboard the Enterprise as a "miracle worker." This was brought about by his reputation for being able to effect starship repairs faster than usually required. Scott later admitted that he often padded his estimates of time needed for repairs by a factor of four in order to appear that much faster.

Scott managed to rid the Enterprise of the tribbles which had infested the ship. by beamed them aboard a Klingon ship where they would be "no tribble at all".

In 2270, Commander Scott played an instrumental role in the massive refit of the USS Enterprise while serving under Captain Will Decker.

In 2285, Scott was promoted and reassigned to the USS Excelsior as Captain of engineering during the ship's early test runs. Scott detested his assignment aboard the Excelsior, citing the ship as little more than a "bucket of bolts", and didn't particularly care for Captain Styles either. He later sabotaged it to stop it chasing Kirk.

Besides Scott, only one other captain, the sciences division's Krasnovsky, has ever been portrayed as wearing captain rank insignia on a uniform not of the command division.

In 2286, Scott traveled back in time to 1986 along with the rest of the Enterprise crew to find a pair of humpback whales. In order to construct a water tank for them, he visited the Plexicorp facility as "Professor Scott" from Edinburgh. Making a deal with plant manager Nichols he gave him the formula of transparent aluminum in exchange for a sheet of plexiglass. When Dr. McCoy objected against "changing the future," Scott pointed out "How do we know he didn't invent the thing?". After returning home he was reassigned as chief engineer of the newly commissioned USS Enterprise-A. He then spent nearly a year refitting the ship for service.

Scott appeared as a "guest of honor" aboard the launch of the USS Enterprise-B. When the Enterprise-B responded to the distress call of two El-Aurian transports, he assisted in rescuing a small group of survivors.

In 2294, following his retirement from Starfleet, Scott traveled aboard the USS Jenolan to the Norpin colony, where he planned to spend his retirement. The Jenolan, however, encountered a Dyson sphere en route, and while attempting to investigate it, the transport crashed on its surface. Scott and fellow engineer Matt Franklin were the only survivors. Together they rigged the Jenolan's transporter systems, and existed for nearly 75 years in the ship's transporter buffer.

In 2369, Montgomery Scott was rescued by the USS Enterprise-D, but Franklin's pattern was too degraded to be recovered. After Scott helped rescue the Enterprise-D from the Dyson sphere, Captain Picard rewarded him with the Enterprise's shuttlecraft Goddard.

Sometime before 2387, Montgomery Scott discovered the necessary formulas enabling transwarp beaming, which Spock would later give to a younger Scott in 2258 of an alternate reality.