The BAFTA Award for Best Original Screenplay is a British Academy Film Award presented annually by the British Academy of Film and Television Arts (BAFTA) to a screenwriter for a specific film.

The British Academy of Film and Television Arts (BAFTA) is a British organisation that hosts annual awards shows for film, television, children's film and television, and interactive media.

In the following lists, the titles and names in bold with a gold background are the winners and recipients respectively; those not in bold are the remaining nominees.

The British Academy of Film and Television Arts (BAFTA) award for Best Original Screenplay has been presented to its winners since 1984, when the original category (BAFTA Award for Best Screenplay) was split into two awards, the other being the BAFTA Award for Best Adapted Screenplay and Best Original Screenplay.

Woody Allen holds the record for the most wins with four awards.