Precursor or Precursors may refer to:
- Precursor (religion), a forerunner, predecessor
- The Precursor, John the Baptist
Science and technology
- Precursor (bird), a hypothesized genus of fossil birds that was composed of fossilized parts of unrelated animals
- Precursor (chemistry), a compound that participates in the chemical reaction that produces another compound
- Precursor (physics), a phenomenon of wave propagation in dispersive media
- Precursor in the course of a disease, a state preceding a particular stage in that course
- Precursor cell (biology), a unipotent stem cell
- Earthquake precursor, a diagnostic phenomenon that can occur before an earthquake
- Gehrlein Precursor, a glider
- LNWR Precursor Class (disambiguation), classes of passenger locomotives developed for the London and North Western Railway
Fiction
- Precursors Halo (series), an extremely advanced race that preceded and were destroyed by The Forerunners
- Precursor (novel), a 1999 novel set in C. J. Cherryh's Foreigner universe
- Precursors, a fictional race (now extinct) of ancient beings in the board game Cosmic Encounter
- Precursors, a fictional alien race in the Star Control video game series
- Precursors, a fictional race of ancient beings in the video game Jak and Daxter: The Precursor Legacy
- Precursors, a fictional alien race in Galactic Civilizations II: Dread Lords video game
- Precursors, a fictional, almost extinct alien race that supposedly created humanity in the Assassin's Creed series
- Precursors, a fictional, evil alien race that created the Kaiju in the movie Pacific Rim and its sequel Pacific Rim: Uprising
- Precursors, a fictional and extremely advanced alien race in the video game Subnautica.
Other
- Precursors of film
- The Precursors (video game), a video game from Kyiv-based developer Deep Shadows