Demon Slayer has 4 seasons of the anime series as of now. The seasons cover different arcs from the manga, with the first season airing in 2019 and the fourth season airing in 2024. After these four seasons, a film trilogy adapting the "Infinity Castle" story arc premiered in July 2025. Here is a summary:

• Season 1: 26 episodes (2019)
• Season 2: 18 episodes (2021-2022)
• Season 3: 11 episodes (2023)
• Season 4: 8 episodes (2024)
• Following the fourth season, a film trilogy adapts the next major arc instead of a fifth season for now.

So, there are currently 4 anime seasons of Demon Slayer, with continuation through films adapting later story arcs.