The two stars are in talks to lend their voices to the upcoming big screen animated feature, "Rio," according to The Hollywood Reporter.
"Rio" centers on the adventures of a nerdy macaw who leaves the comforts of his cage in chilly Minnesota for the exotic city of Rio de Janeiro.
Production is slated to begin later this year, with an April 2011 release date planned.
Also in talks to join the cast is former "Lost" and "300" star Rodrigo Santoro.
Both Hathaway and Harris have delved into the animated world before – Hathaway lent her voice to 2005's "Hoodwinked!" while Emmy host Harris voiced a character in the recent release "Cloudy With a Chance of Meatballs."
Hathaway, who last appeared in "Bride Wars," will next be seen in the ensemble romantic comedy "Valentine's Day," opening in February 2010, alongside Julia Roberts, Jessica Biel, Jessica Alba, Jennifer Garner, Bradley Cooper, Ashton Kutcher and many more.
She recently wrapped production as the White Queen in Tim Burton's "Alice In Wonderland."
Fresh off his gig as host of the Emmys, Harris – who also stars in CBS' "How I Met Your Mother" — is currently filming the teen romance film "Beastly," opposite Vanessa Hudgens and Mary-Kate Olsen.