A script doctor is a writer or playwright hired by a film, television, or theatre production company to rewrite an existing script or improve specific aspects of it, including structure, characterization, dialogue, pacing, themes, and other elements. They are usually brought in for scripts that have been almost "green-lit" during the development and pre-production phases of a film to address specific issues with the script, as identified by the financiers, production team, and cast.

Script doctors generally do their work uncredited for a variety of commercial and artistic reasons. For instance, to receive credit under the Writers Guild of America screenwriting credit system requires a second screenwriter to contribute more than 50 percent of an original screenplay or 33 percent of an adaptation.

  • Carrie Fisher: Hook (1991), Sister Act (1992), Lethal Weapon 3 (1992), The River Wild (1994), An Entertainment Weekly article from May 1992 described Fisher as "one of the most sought-after doctors in town." When asked if she was still working as a script doctor in December 2008, she said: "I haven't done it for a few years. I did it for many years, and then younger people came to do it and I started to do new things. It was a long, very lucrative episode of my life. But it's complicated to do that. Now it's all changed, actually. Now in order to get a rewrite job, you have to submit your notes for your ideas on how to fix the script. So they can get all the notes from all the different writers, keep the notes and not hire you. That's free work and that's what I always call life-wasting events." Foreign Correspondent (1940), Cornered (1945), Gilda (1946), Rope and Cry of the City (1948), Strangers on a Train (1951), Angel Face (1952), and Cleopatra (1963). According to a November 1999 article from The Guardian, "[Uncredited script doctoring is] a tradition that goes back to the mighty Ben Hecht. Hecht was a snob, and hanging out at the Algonquin with Dorothy Parker, it suited him to downplay his movie work, so he only received credit for about half of the 100 plus films he worked on."
  • Herman J. Mankiewicz: Monkey Business (1931), Horse Feathers (1932), Million Dollar Legs (1932), The Wizard of Oz (1939)
  • Tom Mankiewicz: The Deep (1977), The Spy Who Loved Me (1977), Superman (1978), Moonraker (1979), and Superman II (1980). He was credited as "creative consultant" on Superman by director Richard Donner. In a June 2012 interview, Robert Crane, who co-wrote Mankiewicz's autobiography My Life as a Mankiewicz (2012), said: "I think script doctoring was an in road for him. People had liked what they'd seen with the Bond films, especially the dialogue. I think that caught the attention of agents and studio heads, and they said, 'I want Mankiewicz to come in here and work on this project.' He spent a lot of time at Warner Brothers and Universal working on scripts."
  • Elaine May: Reds (1981), Tootsie (1982), and Labyrinth (1986).
  • Aaron Sorkin: Schindler's List (1993), The Rock (1996), Excess Baggage (1997), and Enemy of the State (1998). In an October 2010 interview, Sorkin told a journalist: "With the script doctoring, I did it for Jerry Bruckheimer for a while, because I was just going through a period where I was having a very difficult time coming up with my own ideas and I was climbing the walls. So I did what is called 'the production polish', where you are brought into the last two weeks on something that you are not emotionally invested in, where it is not your job to break the story, to come up with the moving parts and plot points. Basically, they just wanted some snappy dialogue for Sean Connery and Nicolas Cage. The first time I did it, actually, was for Schindler's List where no-one is looking for snappy dialogue, but the writer of that movie had gone on to direct a picture and there was a little more work that [director Steven Spielberg] wanted done before it went to Poland to begin shooting. He asked me to come in and do that, but you are obviously more interested in your own thing."
  • Sir Tom Stoppard: Indiana Jones and the Last Crusade (1989), Sleepy Hollow (1999), and The Bourne Ultimatum (2007). On The Bourne Ultimatum, Stoppard said in October 2007, "I wrote a script for [director] Paul Greengrass. Some of the themes are still mine—but I don't think there's a single word of mine in the film." and Crimson Tide (1995).
  • Robert Towne: Bonnie and Clyde (1967), The Godfather (1972), and Armageddon (1998). Coppola won the Academy Award for Best Writing (Adapted Screenplay) and thanked Towne.
  • Joss Whedon: Speed (1994), The Quick and the Dead (1995), Waterworld (1995), Twister (1996), and X-Men (2000). In a 2013 interview published by Den of Geek, de Souza acknowledged his role as a script doctor. "I still get brought on to fix screenplays that I had nothing to do with. When a movie is about to be shot and they hire me to come in and fix the script and punch it up at the last minute. In addition, I’m like a patient resuscitator who they can hire secretly after a movie has had a horrible test to rewrite some scenes and re-cut the movie so they can make it good enough to get to home video. That’s my secret identity."