Scarlett Johansson is set to become the highest paid actress in Hollywood by raking in $25 million to star in her own Black Widow movie, DailyMail.com can exclusively reveal.

Superstar Scarlett, 33, has signed up to return as Natasha Romanoff for a one-off superhero film, expected to hit theaters in 2020.

Marvel and Disney have agreed to the $25 million deal which will make the mother-of-one Hollywood's highest paid actress for a single movie.

It is understood Scarlett's agents are also negotiating for her to get a producer's credit on the Walt Disney Pictures production.

Insiders say that should the movie - based on the comic book heroine - generate more than $900 million, the star will also get an estimated $6 million bonus check.

This means Scarlett could walk away with around $31 million, made up of wages, perks, and bonus, if the movie explodes at the box office, which given the franchise's history - is very likely.

Scarlett Johansson is set to become Hollywood's highest paid actress with a $25m deal with Marvel and Disney for a stand-alone Black Widow film, a source told DailyMail.com

Marvel has just hired screenwriter Jac Schaeffer to write the script for the long-awaited stand-alone movie, an insider revealed.

Schaeffer and Scarlett are understood to be 'working closely' together on the development of the plot.

The Black Widow character originated on the big screen with Scarlett in Iron Man 2 and she has since appeared in five other Avengers movies.

Fans will next see Black Widow in Avengers: Infinity War, released this summer, then the follow up film in 2019.

A well-placed film industry source told DailyMail.com: 'Scarlett will get a huge pay day for the Black Widow film, which Disney believes could eclipse Wonder Woman in terms of a female-led superhero film's revenue.

'She has been a lucky charm for the studio in all their films, and brings her A-game during each performance.

'Scarlett is adored by Disney's top brass and is a real team player. This stand-alone movie is out there for them, but they feel it can make history.

'The wages are high, but nothing she doesn't deserve given her track record as this character.'

The source added that Scarlett will also get a revenue bonus if the movie does well at the box office, meaning she could walk away with $31m. The insider said: 'Her wages are getting closer to those of her male co-stars and leading men, but a big step away from Robert's deals'

The huge pay bump puts Scarlett ahead of Hollywood sweethearts Emma Stone and Jennifer Lawrence, who in 2017 made $26 million and $24 million, respectively

The source added: 'Her agents have pushed through the revenue bonus payment. If it makes over $900 million at the box office then she will get another $6 million.'

The Black Widow film has Jude Law and Ben Mendelsohn as potential co-stars.

The source added: 'The script is being written and the hopes are to have the stand-alone film in cinemas by summer 2020.'

Marvel, which is notoriously secretive when it comes to its stars, refused to confirm the deal.

Despite the huge payday for Scarlett, the figures are still low compared to Robert Downey Jr, who earned a starting salary of $50 million before bonuses for his role as Tony Stark/Iron Man.

The news comes following reports that Mark Wahlberg's co-star Michelle Williams made less than $1,000 for re-shoots on Ridley Scott's movie All The Money In The World, while Wahlberg bagged $1.5 million.

After a flurry of media attention Wahlberg announced that he will donate his wages to the Time's Up legal fund against sexual abuse and harassment, saying he supports the 'fight for fair pay' initiative.

Scarlett is one female actress who has been pushing the wage boundaries with her role as Black Widow. She is understood to be currently earning $20 million for the latest Avengers film.

Despite the 33-year-old's breakout deal, her payday is small in comparison to the $50m Robert Downey Jr made when he started out in his role of Tony Stark/Iron Man

Gal Gadot earned just $300,000 for playing Wonder Woman last year even though the DC and Warner Brothers flick earned over $600 million.

Jeff Kelly of US entertainment marketing firm JDMC said: 'Scarlett is a seat filler, audience pleaser and a brilliant actress.

'She has been astonishing in this franchise, and so deserves the deal and the payment. It is not unfathomable that she could earn over a billion if the script is right.

'Her wages are getting closer to those of her male co-stars and leading men, but a big step away from Robert's deals.

'This makes her the highest paid female actress for a one-off film.'

Meanwhile, Chris Evans, who plays Steve Rogers aka Captain America, takes home around $7 million, with Jeremy Renner and Chris Hemsworth both earn $6.5 million with bonuses for box office sales.

Mark Ruffalo makes around $3.2 million for the Hulk with bonus add-ons too.