The Canceled Star Trek Sequel Series That Fans Will Never Get To See

Though the "Star Trek" franchise has become one of Paramount's biggest success stories, with its shows frequently appearing among the best series to ever grace UPN and its films becoming box office hits, one TV project was canceled before ever making it to air: "Star Trek: Phase II." 

After NBC made the short-sighted decision to cancel "Star Trek: The Original Series" after three seasons in 1969, Paramount Studios toyed with the idea of reuniting William Shatner, George Takei, and other co-stars for more adventures in "Phase II," a '70s revival series. (The project excluded Leonard Nimoy, who had legal issues with "Star Trek" creator Gene Roddenberry at the time.)

With "Phase II," Paramount hoped to create a show that boasted slick '70s production values and reintroduced "Star Trek" to the next generation of fans. So, what stopped the crew of the U.S.S. Enterprise from taking flight once again?

Early on, it looked like "Phase II" might be smooth sailing. Paramount hoped the revival series could spearhead a new TV network, and "Phase II" pre-production got underway. Walter Koenig and Takei — both of whom starred on "Star Trek: The Original Series" — were officially set to return. The studio was also hopeful that Shatner and other blasts from the past would reprise their roles, while Persis Khambatta and David Gautreaux signed on to play Lieutenant Ilia and Xon, respectively. 

But that network never came to fruition — though 20 years later, the studio launched United Paramount Network (UPN) alongside "Star Trek: Voyager" — and "Phase II" was ultimately abandoned for financial reasons. While the TV project fell by the wayside, Paramount did go on to bring back original cast members, including Nimoy, in 1979's "Star Trek: The Motion Picture." (Several "Star Trek" film projects had been in the works at various points throughout the '70s, but it was the Robert Wise-directed 1979 feature that ultimately made the cut.)

Though the cast never got to reunite in "Phase II," the original series still delivered plenty of memorable "Star Trek" moments worth celebrating. And despite the premature cancelation of "Phase II," the franchise has become a television juggernaut. Even in the streaming age, "Star Trek" has cemented itself as a viable entity with "Strange New Worlds," which was renewed at Paramount+ for a fifth and final season in June 2025.