The 32-year-old singer met Hathaway at an organic eatery in LA and the duo gushed about their admiration towards each other's work, reported Us Magazine.
"She said to Beyonce, 'I love your music.' And Beyonce told Anne, 'And I love your movies and I cry every time I watch them!," a source said.
The 'Halo' hitmaker and her rapper husband Jay Z have embarked on a 22-day vegan challenge until Christmas Day.