A Mary Poppins sequel to the 1964 Disney classic will feature Emily Blunt as the magical nanny.
The British actress will follow in the footsteps of Julie Andrews in the film, which is set to be released on Christmas Day in 2018.
Mary Poppins Returns will the tell the story of an older Jane and Michael Banks and Michael's three children, who are visited by Poppins in the aftermath of a "personal loss" in Depression-hit London, Walt Disney Studios said.
Rob Marshall, whose previously worked on Chicago and Into The Woods, will direct the film, while the script is being produced by Finding Neverland writer David Magee.
Lin-Manuel Miranda will also star.
The first Mary Poppins book was written in 1934 by PL Travers, who went on to write seven additional sequels up to 1988.
The film, which was directed by Robert Stevenson and starred Andrews and Dick Van Dyke, won five Oscars, including Best Actress for Andrews.
Blunt, 33, whose previous films include Sicario and The Huntsman: Winter's War, is currently expecting her second child with her husband, actor John Krasinski.