The Oscar-winning actress wore a strapless, above-the-knee Dolce & Gabbana dress as she joined fellow stars Tom Hanks, Susan Sarandon, Jim Broadbent and Jim Sturgess on the red carpet at Grauman's Chinese theatre.
USA Today reports that Halle said she couldn't say no to a part in the epic, centuries-spanning film, based on British author David Mitchell's novel.
The 'Monster's Ball' star plays several roles in the film, including a man.
She told reporters at the premiere: "You have to say yes to something like this."
Halle - who was joined by fiance Olivier Martinez - said she hoped people "walk away having a dialogue about it".
She added: "And really realising the ramifications of all of our actions and all of the choices that we make, and that they do reverberate for generations and generations. Acts of kindness and also acts of cruelty. It really matters."