Josh Hartnett: Sienna Miller’s Rebound?

Josh Hartnett seems to be getting the most out of his stay in London.

The 30-year-old actor is currently in the British capital performing in the stage production of Rain Man. But off-stage, it seems to be raining women for the Black Dahlia star.

First he was rumored to have gotten busy with an unknown female in the library at his hotel. Soon after, he supposedly shared some intimacy with 22-year-old O.C. vet and noted philanthropist Mischa Barton.

Hartnett’s latest alleged conquest? Sienna Miller, who’s newly single after her split with Brothers & Sisters actor Balthazar Getty.

Hartnett and Miller, 26, were spotted leaving Jalouse nightclub at the same time last week. Now Contact Music is reporting that the budding couple had a hush-hush get-together at the exclusive Shoreditch House private bar in East London.

“They definitely looked like a couple—and a good-looking one at that! At one point, they were holding hands across the table, but they quickly hid them underneath,” the paper’s source states. “They continued talking and drinking until very late into the evening—there was definitely a buzz in the air.”

Hmm; that seems odd; Sienna usually likes ‘em a little more attached. Perhaps she confused Hartnett with his single-but-committed doppelganger, Johnny Depp.