The César Award for Best Original Screenplay () is an award presented by the Académie des Arts et Techniques du Cinéma. It was initially awarded from 1983 to 1985, and then awarded again in 2006, when the original category (César Award for Best Original Screenplay or Adaptation) was split into two awards, the other being César Award for Best Adaptation.
The César Award for Best Original Screenplay or Adaptation was awarded from 1986 to 2005.