The two were seen at George restaurant for LOVE magazine’s Christmas party on Friday, and both looked to be in the holiday spirit.
Photos of the outing show Miller sporting a wide grin as she dons a green coat over a red ensemble. Sturridge is seen in a brown hat and a Christmas sweater.
Miller and Sturridge announced their split in July after four years together. However, a source close to the couple previously told PEOPLE that the split may not be a definitive end for the pair.
“They are over, but don t rule out a reunion,” the source said. “Tom wanted to get married and have more children. Sienna didn’t. This year everything exploded with Tom in London and Sienna leading a separate life in the U.S and [her appearance at] Cannes.”
After being photographed holding hands on set in Los Angeles, a source told PEOPLE that “there are no signs of romance between them.”
The source added: “[Affleck] has had some special scenes with Sienna, including kissing scenes. They seem to get along great, but Ben has acted very professional.”