Hathaway is in talks to take over Reese Witherspoon's role after the latter actress left the project in January due to scheduling conflicts, reports The Hollywood Reporter.
The Intern tells the story of an internet company owner who gets assigned a retiree intern.
The trainee, played by De Niro, becomes valuable to the owner, and the pair develop a relationship.
The Intern is helmed by Nancy Meyers, who previously directed It's Complicated, The Holiday and Something's Gotta Give.
Hathaway is starring in Christopher Nolan's upcoming sci-fi movie Interstellar, which is planned for a November 7 release in the US and UK.
Meanwhile, Witherspoon will be seen next in Wild, based on Cheryl Strayed's memoir.
Watch a trailer for Interstellar below: