The popular British series ended in March and the 34-year-old actress, who played Lady Mary Crawley in it, said she would love to reunite with her former costars, reported People magazine.
"I think there is potential for a film. That is something I would wholeheartedly consider, so we will see. It may not be over yet.
"The thing that I miss the most are my cast members. But we are all still very close," Dockery said.
The actress will next be seen in the upcoming TNT series, "Good Behavior."