Star seed or starseed may refer to:

• Starseed, a 1973 book by Timothy Leary
• Star Seed, a 2021 single by Loona
• Starseed (band), South-African/British rock band
• Starseed (novel), a 1991 science fiction novel by Spider Robinson and Jeanne Robinson
• "Starseed" (song), a 1994 single by Our Lady Peace
• Starseed launcher, a hypothetical concept of a space exploration system
• Starseeds, fictional microorganisms used by Outsiders to seed new planets with life in Larry Niven's Known Space science fiction series
• Star seeds, a type of crystal in sentient life in the Sailor Moon: Sailor Stars series
• Star people (New Age), individuals who state they have originated from another planet or Galaxy
• A giant machine hypothetized to be able to collapse black holes among other things, in the video game Solar Ash. The McGuffin of the game's story.