The two-minute film, which launched on YouTube this week, tells the 50-year story of the relationship of Edward and Doris, who meet in 1967 when she was an air stewardess and he was a passenger.
The pair are shown continuing to meet again at Heathrow at Christmas time over the years, with a second and then third generation of bears eventually appearing in the scenes.
The film was directed by Dom&Nic through Outsider Productions, and with a soundtrack featuring Petula Clark's 1966 hit 'Couldn't live without your love'.
Last year, the bears featured in a film that highlighted the "iconic experience" of travelling through the airport and the joy of coming home at Christmas.
Heathrow commercial director Ross Barker said: "After an overwhelming response across the globe to Doris and Edward last year, we had to bring these lovable bears back to our screens. We wanted the advert to make people feel even more excited to welcome friends and family this festive season."
Seasonal surprises - with PR at the heart
Heathrow head of PR Nadia Vere told PRWeek there would also be a series of surprises to discover across Heathrow's terminals throughout the Christmas period, as well as Doris and Edward interacting with people on social media.
Vere said: "Additionally, passengers making a booking or purchase through our personal shopping service will also receive a limited-edition scarf designed by Karen Mabon, which has drawings of people reuniting, as well as the bears hidden within it."
Vere said PR "had always been integral to any of Heathrow’s marketing campaigns... which is why our plan to launch this year’s Christmas campaign was fully integrated across PR and media engagement."
A version of this article first appeared on PRWeek sister title Campaign