It’s war between Bradley Cooper and Justin Timberlake – as the two hunks duke it out for the affections of “House” hottie OLIVIA WILDE.

The newly single “Hangover” star and the “SexyBack” singer are both dating Olivia, who recently filed for divorce.

And the two Romeos are both so intent on emerging the winner, they nearly came to blows over the actress, say sources.

“Justin and Bradley are fighting like dogs over Olivia – and she loves that they’re going nuts over her,” revealed an insider.

In March, Olivia, 27, filed for divorce from her husband of almost eight years, Italian prince Tao Ruspoli.

A few weeks earlier, Justin and Jessica Biel had announced their split after four years together, while Bradley and Renee Zellweger also broke up in March.

“Tron” star Olivia and multi-talented Justin, 30, first met while filming “Alpha Dog” in 2006 and star together in the upcoming thriller “Now.”

They were first spotted getting close April 2 at the Roxbury club in Los Angeles.

The hunks’ rivalry burst spectacularly into the open at a May 21 party, say sources.

“Olivia was all over Bradley – and Justin was left to stew,” said the insider.

“Finally he walked up to Bradley and said, ‘What’s your problem, man? Olivia’s with me.’

“It looked like the two might start fighting, but Bradley laughed and walked away – which only infuriated Justin more.”