Majel Barrett, who would later marry Gene Roddenberry, made her Star Trek debut in "The Cage" (1964), Roddenberry's original pilot. She played "Number One", Captain Pike's unnamed first officer. She would later play Nurse Chapel (ST:TOS), Lwaxana Troi (ST:TNG) and M'Ress (ST:TAS), as well as the voice of the ships computer in multiple incarnations of the series.

Livingston was a lionfish kept by Captain Jean-Luc Picard in his ready room aboard the U.S.S. Enterprise-D for the duration of the ship's existence. The fish has its own trading card in the ST:TNG card series.

Geordi's VISOR was originally improvised from an automotive air filter and a hair band.

The Tantalus field was a 23rd century device found aboard the I.S.S. Enterprise in the mirror universe, which could be used to monitor and eliminate enemies from existence with the touch of a button.

In "Relics", the crew of the U.S.S. Enterprise-D discovers Montgomery Scott alive in a transporter buffer while investigating the 75-year-old wreck of a Federation transport vessel.

DeForest Kelley appeared as 137-year-old Leonard McCoy in "Encounter at Farpoint", the pilot episode of Star Trek: The Next Generation, reprising his role from the original series. As he inspects the Enterprise-D, he tells Data, "You treat her like a lady ... and she'll always bring you home."

In "The Naked Now", Tasha Yar asks Data if he is "fully functional". He replies that he is not only functional "in every way", but also "programmed in multiple techniques." "Oh you jewel," Tasha says, "that's exactly what I hoped!"

A Starfleet Science Officer and Lieutenant Commander on the U.S.S. Shenzhou, Saru is Kelpien, an alien prey species that have biologically evolved the ability to sense threats.

The final episode of the Original Series deals with gender inequality. A bitter woman steals Captain Kirk's body in order to take command of the Enterprise, an opportunity that she feels has been unfairly denied her. Kirk's last words are: "Her life could have been as rich as any woman's, if only ... If only ..."

Martin Landau was originally offered the role of Spock, but declined. Later, Leonard Nimoy, who did accept the part, took over the role of the disguise-expert on "Mission: Impossible" when Landau left that show. Landau later headed his own sci-fi series, "Space: 1999" (1975).