• Acting for Two: Jerry Stiller as Frank Costanza, and the implied relative Giuseppe in "The Doll", poorly disguised by Seinfeld standards, even compared to Jerry Seinfeld and Jason Alexander playing their characters in high school in "The Library".
  • Actor Allusion: In the JFK parody in "The Boyfriend," Newman replicates his position standing in front of Kramer, just as Wayne Knight did in the movie standing in for John Connally in the courtroom demonstration of the "magic bullet" theory.
    • A picture of a dinosaur appears in Newman's apartment, referencing Knight's role in Jurassic Park.
  • The Danza: Jerry Seinfeld's character is named... "Jerry Seinfeld".
    • George's mother Estelle is named after her actress. But they couldn't name his father the same way because they already had a Jerry.
    • But, George's dad was originally played by John Randolph.
    • In "The Kiss Hello", Wendie Malick as Wendie the delicate genius.
  • Descended Creator: As the show went on, Larry David had more and more Creator Cameos usually seen only from behind or voicing unseen characters like George Steinbrenner, a part David continued to voice for some time after he had already left the series as a writer.
  • Directed by Cast Member: Jason Alexander directed Season 3's "The Good Samaritan".
  • Dueling Shows: With Everybody Loves Raymond.
  • Edited for Syndication: Most episodes feature little dialog cuts here and there to save time for more commercials.
    • The episode which suffers the worst in this regard is "The Yada Yada", as it originally ran 26 minutes in its NBC premiere.
  • Fake Brit: Norman Brenner's character in "The Wig Master".
    • Subverted. Brenner is actually British.
  • Hey, It's That Guy!: Hey, it's Monica, Janice, Susan, Daphne, Kitty, Robert, and even a youthful Dr. Cuddy!
  • Hey, It's That Voice!: J. Peterman's actor can unmistakably be heard as the voiceover in current Coors Light commercials.
  • What Could Have Been: Larry Miller was originally cast as George, but it was decided that, just to make George a little bit more pathetic, he needed to be short. Miller eventually appeared as a doorman that could give The Janitor a run for his money.
    • The project began as just a 90 minute special about a day in Jerry's life, and how it inspires his stand-up material that night. Jerry and Larry David couldn't quite stretch the script to fill the 90 minutes, so they reduced in down to half an hour as a series pilot. As Jerry would later say, "We couldn't make 90 minutes, so we made 90 hours."
    • Elaine's father was intended to be a recurring character, but then they hired the notoriously ill-tempered and intimidating Laurence Tierney to play him, and after filming the episode, no one wanted to work with him again.