The couple wed in a Jewish ceremony at a private residence near Big Sur, California on Saturday night (04Aug12), in front of family and friends including socialite Ivanka Trump, UsMagazine.com has confirmed.
No further details about the nuptials were available as WENN went to press.
The Oscar-winning actress, 31, began dating Frenchman Millepied, 35, in late 2009 after meeting on the set of Black Swan.
Portman announced she was engaged and pregnant in December, 2010 and they became parents to son Aleph the following June (11).
The wedding news comes six months after the stars sparked speculation they had secretly become husband and wife after wearing matching bands on their ring fingers while attending the Academy Awards in February (12). The fiercely-private couple refused commented on the rumours.