The movie - which carries on from where the sixth series of the ITV drama left off - is due for cinema release in autumn 2019.
Harewood House, the grand stately home between Leeds and Harrogate, is one of the locations that appears in the film and scenes were shot on the estate back in October.
However, the country house is not included in the short trailer, which instead features sweeping, panoramic shots of Highclere Castle, which stands in for the fictional Downton Abbey.
Stars including Hugh Bonneville and Elizabeth McGovern were spotted in 1920s costume for what appeared to be a party scene at the Harewood estate during the autumn shoot.
Bonneville, who plays Downton's patriarch Lord Grantham, was snapped in black tie while his on-screen wife Lady Grantham, played by McGovern, was attired in period evening dress and a tiara.
Why Downton Abbey is forever YorkshireLaura Carmichael, who plays their daughter Lady Edith, was also on the set, as was Penelope Wilton, who appears as family friend Isobel Crawley. Some of the actresses were wearing Ugg boots and puffa jackets to keep warm between takes.
As Highclere Castle in Hampshire is used as the location for Downton, is it likely Harewood is standing in for another country house, possibly owned by friends of the Granthams, in the upcoming movie, which is set in the 1920s. Vintage cars were also spotted on the set.
Harewood itself enjoyed a prominent period in its history during the 1920s, as the sixth earl, Henry Lascelles, had married Princess Mary, the daughter of King George V, in 1922. Their first marital home was at Goldsborough Hall, but when Henry inherited the earldom in 1929 they moved into the main house.
It's not the first time Harewood has starred in a costume drama - it stood in for Buckingham Palace in the ITV series Victoria, about the life of Queen Victoria.
Downton Abbey is a fictional North Yorkshire estate and towns such as Easingwold, Thirsk and Ripon are referenced throughout the six series of the show.