Great Britain in the 19th century: Dr. Dolittle (Robert Downey Jr.) was once a famous doctor and veterinarian. But when he lost his wife seven years ago, he completely retired. He now lives like a hermit behind the high walls of his property, almost without contact with other people. Only his animals, with which the doctor can even speak, keep him company – such as the headstrong parrot lady Polynesia (voice: Emma Thompson), who supports Dolittle with advice and action, the cynical ostrich Plimpton (Kumail Nanjiani) or the always freezing polar bear Yoshi (John Cena). When young Queen Victoria (Jessie Buckley) falls seriously ill, Dolittle has no choice: he has to go out into the wide world to find the cure. But for that he has to find the mysterious island that his wife once died looking for.