If you mean KNY / Demon Slayer: Kimetsu no Yaiba , the anime has 4 TV seasons so far. The manga is complete, with 23 volumes in total, and the anime is still adapting the later arcs.

Seasons so far

  • Season 1
  • Mugen Train / Entertainment District follow-up era
  • Swordsmith Village arc
  • Hashira Training arc

Manga note

The manga has already finished, so there isnā€™t a fixed ā€œnumber of seasonsā€ in manga formā€”just the full story across its completed run.

Quick scoop

A lot of fan discussions historically guessed there would be several more seasons as the manga adapted out, but the current anime count is still 4 seasons.

If you want, I can also list the seasons in watch order with their arcs.