Meghan was out and about with Archie and Harry on Wednesday at a charity polo match with the Cambridges.
The couple will meet some of the cast and crew before watching the film, and afterwards greet representatives from organisations doing groundbreaking work in the areas of conservation and the environment.
Disney has announced its global conservation campaign Protect the Pride to mark the movie’s release.
With conservation partners and the Royal Foundation, the drive aims to raise awareness and support efforts to recover the dwindling lion population across Africa.
Buckingham Palace said: “The Duke of Sussex has taken a deep personal interest in frontline conservation projects that work to protect Africa’s natural heritage and support both wildlife and local communities.”
Harry and Meghan are taking baby Archie to South Africa in the autumn.
The duke is also carrying out solo visits to Angola, Malawi and Botswana.
The Sussexes’ approach to privacy has made headlines after they decided not to reveal details of Archie’s godparents following his private christening, and after a royal protection officer asked a Wimbledon fan, who was photographing Serena Williams, not to take pictures of Meghan.