Mary Poppins is a series of children's books written by P.L. Travers and originally illustrated by Mary Shepard. The books centre on a mysterious, vain and acerbic magical English nanny, Mary Poppins. She is blown by the East wind to Number Seventeen Cherry Tree Lane, London and into the Banks' household to care for their children. Encounters with chimney sweeps, shopkeepers and various adventures follow until Mary Poppins abruptly leaves, i.e., 'pops-out'. The adventures take place over a total of eight books. However, only the first three books feature Mary Poppins arriving and leaving. The later five books recount previously unrecorded adventures from her original three visits. As P.L. Travers explains in her introduction to Mary Poppins in the Park, 'She cannot forever arrive and depart.'

The books were adapted in 1964 into a musical Disney film starring Julie Andrews and Dick Van Dyke. In 2004, Disney Theatrical produced a stage musical adaptation in the West End theatre. The stage musical was transferred to Broadway in 2006. It is still running there to this day, to sold out crowds. It has been highly successful, as was the classic 1964 film.

The first book introduces the Banks family, consisting of Mr. Banks and Mrs. Banks and their children Jane, Michael, and baby twins John and Barbara. When the children's nanny, Katie Nana, storms out in a huff, Mary Poppins arrives at their home, complete with her traveling carpetbag, blown in by a very strong wind. She accepts the job, and the children soon learn that their nanny, though she is stern, vain, and almost always cross, has a magical touch that makes her wonderful. Among the things Jane and Michael experience are a tea party on a ceiling with Mr. Wigg, a trip around the world with a compass, the purchase of gingerbread stars from the extremely old Mrs. Corry, a meeting with the Bird Woman, a birthday party at the zoo among the animals, and a Christmas shopping trip with a star named Maia from the Pleiades cluster of the Taurus constellation. In the end, Mary Poppins is satisfied with the work she has done with the Banks family, and the West Wind carries her away.