The Tudors and Game of Thrones star is eyeing a supporting role in the movie, according to The Hollywood Reporter.
Scott will direct the thriller, which has been written by Cormac McCarthy (No Country for Old Men, The Road).
The Counselor centres on a lawyer (Michael Fassbender) who is in desperate need of money and becomes involved in cocaine trading on the Mexican border.
The movie also stars Brad Pitt, Javier Bardem (Skyfall), Penelope Cruz, Cameron Diaz and Breaking Bad actor Dean Norris.
Fassbender was photographed filming scenes for the movie in London earlier this week.
Dormer, whose other previous credits include BBC One legal drama Silk, Captain America: The First Avenger and W.E, recently joined the cast of drama A Long Way From Home.
She will also appear in Ron Howard's Formula One movie Rush, which is due for release next year.