One of Hollywood's most private couples stepped out together over the weekend for a very special occasion.
On Saturday, Joaquin Phoenix was joined by fiancee Rooney Mara at the lavish premiere of his new film, Joker. The 34-year-old actress chose a black floral two-piece ensemble highlighting her slim figure. She completed the look with a black headband and pointed black heels.
As for Phoenix, the 44-year-old leading man hit the carpet in a black suit and tie. He also sported a mustache and beard at the rollout for the film, which earned him the Golden Lion at the Venice Film Festival and is already attracting awards season buzz.
Mara and Phoenix started dating in 2016 while shooting the biblical drama, Mary Magdalene, in Rome and Southern Italy. The film was released to stream in April.
Although they are known for maintaining a very low profile, Phoenix and Mara were together at the Cannes Film Festival in 2017 and she was able to congratulate him when he won the Best Actor award for his role in Lynne Ramsay's grim thriller, You Were Never Really Here.
And in August, the pair exuded Old Hollywood glamour while side by side at the rollout for Joker at the Venice Film Festival. Phoenix wore a tuxedo with a bow tie. He also wore dark sunglasses for the massive event. Meanwhile, Mara donned a bold white Givenchy dress with matching satin heels.
Although they didn't pose for photos together, Phoenix was spied admiring his girlfriend amid the fanfare.
Earlier this month, ET spoke with Phoenix about losing over 50 pounds to become the comic book villain in the film. He said that he began by researching the side effects of medication on patients.
"And one thing that everybody was talking about on these [message] boards was how their medications affected their weight. And some people would talk about losing a lot of weight and some would talk about gaining weight," he explained. "And so, I said, 'Let's go with the weight gain' because that would be easier for me. And Todd [Phillips, the film's director] said, 'No, no, no, you are going through weight loss.'"
Phoenix also discussed what drew him to the job: "Because it was complex in a way that other movies I flirted with weren't. And so, I thought that it was gonna be challenging for me as an actor. I thought it was gonna be challenging for the audience. And that's exciting to me."
Joker arrives in theaters on Friday.