- Directors: Kirk Jones
- Producers: Lindsay Doran, Tim Bevan, Eric Fellner
- Writers: Screenplay, Emma Thompson, Books, Christianna Brand
- Genres: Comedy, Family, Fantasy
- Actors: Emma Thompson, Colin Firth, Angela Lansbury, Imelda Staunton, Kelly Macdonald, Thomas Sangster, Eliza Bennett, Jennifer Rae Daykin, Holly Gibbs
Taking place in 19th century England, widower and undertaker 41-year-old Cedric Brown (Colin Firth) has seven children: 12-year-old Simon (Thomas Sangster), 10-year-old Tora (Eliza Bennett), 9-year-old Lily (Jennifer Rae Daykin), 8-year-old Eric (RaphaÃ«l Coleman), 7-year-old Sebastian (Samuel Honywood ), 5-year-old Christianna (Holly Gibbs) and 1-year-old Aggie (Hebe Barnes and Zinnia Barnes). He loves his children very much, but spends little time with them, unable to handle raising them all on his own. The children have had a series of seventeen nannies, whom they systematically drive out; it is a point of pride for them to get rid of each nanny as fast as possible. They also terrorize the cook, Mrs. Blatherwick (Imelda Staunton) but are cared for and loved by Evangeline (Kelly Macdonald), the young scullery maid.
Cedric attempts to hire another nanny from the agency that sent the past seventeen nannies, but the agency refuses him, as the children have sent the past nannies away, terrorized. Desperate to find another nanny, Cedric heeds the advice of a mysterious voice from the house, which says, “the person you need is Nanny McPhee.” After a series of mysterious events, an unusual and hideous woman named Nanny McPhee (Emma Thompson) arrives at Brown home, introducing herself as a “government nanny”. With discipline and magic, she transforms the family’s lives. In the process, she herself transforms from ugly to beautiful. The children, led by Simon, attempt to play their tricks on her, but gradually start to respect her and ask her for advice. They change into responsible people, helping their hapless father in solving the family problems, and making Nanny McPhee less and less needed. (The storyline is, at this point, very similar to Mary Poppins).
Interestingly, not all of the lessons are for the children. In addition, the last one can vary depending on interpretation.