Kaling, 37, has written the script and will produce the movie with Scott Rudin and Howard Klein, said The Hollywood Reporter.
The story follows a venerated late-night talk show host, played by 57-year-old Thompson, who is in danger of losing her long-running show right when she hires her first female writer, played by Kaling.
Sources describe the film as "The Devil Wears Prada" meets "Broadcast News".
No studio is currently attached, but sources say a bidding war for the package is expected to be heated with several bidders already in the mix.