Star Trek: Seinfeld could be the title of a great new series. And we mean it. The overlap between the Star Trek franchise and the long-running sitcom is massive, with more than 30 actors having appeared in both.
The most consequential overlap, to be sure, was made by Seinfeld series regular and uber-Star Trek fan Jason Alexander. The actor, who starred as George Costanza on Seinfeld, guest-starred as the brilliant Kurros on Star Trek: Voyager, in the episode “Think Tank,” which aired in 1999. The character sought to swap the safety of the USS Voyager (as they dodged bounty hunters) for a steep price: Seven of Nine. More recently, Alexander returned to the Trek franchise to voice the character Noum on Lower Decks.
Estelle Harris, who recurred on Seinfeld as George Costanza’s mother, Estelle, also guest-starred on Voyager. She appeared in the third-season episode “Sacred Ground,” which premiered in 1996. She also co-starred in the big-screen comedy Out to Sea alongside Walter Matthau, Jack Lemmon, and… Brent Spiner. Harris passed away in 2022 at the age of 93.
Phil Harris recurred on Seinfeld as the Johnnie Cochran-esque lawyer Jackie Chiles. He was just a child when he popped up in The Original Series episode “Miri,” then later returned to the franchise with roles in Star Trek III: The Search for Spock (as Cadet Foster), Star Trek: Deep Space Nine (as the Klingon Thopok in “Looking for par’Mach in All the Wrong Places” and the Jem’Hadar Remata’Klan in “Rocks and Shoals), and Voyager (as a 21st century astronaut, John Kelly, in “One Small Step.” Harris remains a popular figure on the Star Trek convention circuit.
The late Richard Herd recurred on both Seinfeld and Voyager, and he guest starred in a Star Trek: The Next Generation two-parter, portrayed Mr. Wilhelm, George’s boss during his time with the New York Yankees, across 11 episodes of Seinfeld, and on Star Trek he turned up four times as Admiral Owen Paris, the father of Tom Paris on Voyager, and twice as the Klingon character L’Kor on TNG (in the “Birthright” two-parter).
The actress and comedian Sarah Silverman notched one of her earliest television roles on Voyager, playing the character Rain Robinson in both halves of the “Future’s End” two-parter that aired in 1996. A year later, she guest-starred as Kramer’s girlfriend Emily in the Seinfeld episode “The Money.” Silverman has stated that she didn’t have a good experience working with Kramer actor Michael Richards.
Heidi Swedberg, who recurred as George’s doomed fiancée on Seinfeld, was the Cardassian character Rekelen in the DS9 episode, “Profit and Loss.” Melanie Smith guest-starred as Rachel Goldstein in a trio of Seinfeld episodes and also as the third actress to portray Ziyal, daughter of Gul Dukat, on DS9. Elizabeth Dennehy guest-starred as Allison in the classic Seinfeld installment “The Handicap Spot” and is known as Riker’s nemesis Lt. Commander Elizabeth Shelby, in the TNG two-parter, “The Best of Both Worlds.” She returned as Shelby in the Picard episode “Vox.” Jack Shearer played Mr. Tuttle in Seinfeld’s “The Barber” and several different roles on DS9, Voyager, and in Star Trek: First Contact.
And there’s more: Stephen McHattie, Teri Hatcher, Armin Shimerman, Brenda Strong, Richard Fancy, Michelle Forbes, Tom Wright, Susan Diol, Mark Metcalf, Kellie Waymire, Vaughn Armstrong, Angela Dohrmann, Marty Rackham, Shannon Cochran, Matt McCoy, Margaret Reed, Brian George, Ian Abercrombie, John Fleck, J.G. Hertzler, Mark Harelick, Stephen Root, George Murdock, and Gail Strickland all crossed over between the two shows!