The actor was accompanied by his girlfriend, actress Floriana Lima. While Affleck walked the carpet alone, Lima, who appears on the CW series Supergirl, joined him at the afterparty, where they sweetly showed their affection.
Affleck, 41, and Lima, 33, were spotted holding hands and chatting closely as they mingled with fellow partygoers.
The two have been linked romantically since October, when they were first spotted locking lips during a romantic beach day in Malibu. They’ve stepped out together numerous times since then.
Affleck split from wife Summer Phoenix in March after nearly 10 years of marriage.
Aside from Lima, Ben Affleck also attended the premiere on Monday to support his younger brother.
Manchester By the Sea follows Lee Chandler (Casey Affleck) as he becomes the guardian of his nephew following his brother’s death.
Affleck said it was a challenge to play such a dynamic and oftentimes dark role, adding that he constantly pushed himself to stay in the mindset of his character.
“Whenever it starts to feel easy, it makes me feel like I’m not doing all that I can do,” he said. “It’s a great piece of material, and there are some really hard scenes in there. The first time I read it, I knew there would be a lot of challenging aspects to the performance. I was pretty focused the whole time and was very wary if we started having too much fun, then it might ruin the mood.”
Both Affleck and his costar Michelle Williams are receiving Oscar buzz for their noteworthy performances in the film.
Manchester By the Sea hits theaters Nov. 18.
- Reporting by RAHA LEWIS