The President made the comments at a fundraiser at Harvey Weinstein's home in Connecticut last night, E! Online reports.
Weinstein hosted the event along with Joanne Woodward, Aaron Sorkin and Hathaway, who was described as "spectacular" by Obama.
"I got a chance to see Batman and she was the best thing in it," he said. "That's just my personal opinion."
Obama also praised Sorkin - the former scribe of The West Wing - for writing "the way every Democrat in Washington wished they spoke".
Jerry Springer and Anna Wintour were also present at the fundraiser, which was held to raise money for Obama's re-election campaign.
Speaking at the event, Weinstein said: "Recently in Aurora, we saw [Obama] put his arms around the people that needed him the most. You can make the case that he's the Paul Newman of American presidents."
Sarah Jessica Parker, George Clooney and Glee writer Ryan Murphy are among the other stars who have held fundraisers for Obama, while Julianne Moore, Edie Falco and Nathan Lane will host an event later this month.
Watch the Dark Knight Rises trailer below: