Montgomery Clyde, a British geographer, discovers an intelligent species of bear in the jungles of Peru. The bears, Lucy and Pastuzo, are clever, and can learn to speak English. When he leaves, he tells the bears that they can visit him in London if they like. Clyde leaves and the bears get on with life.
But when an earthquake separates the family members, Lucy sends her nephew to London to find a home there. When he arrives, he does not find a home, but he does find the Browns. Mr. Brown, a risk analyst, brings him home and names him Paddington, after the train station where Mr. Brown found him. But after a series of accidents, Paddington's relationship with the family sours.
So Paddington looks for Montgomery Clyde hoping he can find a home with him. Along the way, he becomes the object of desire of a taxidermist named Millicent. Will Paddington find a safe home before Millicent finds him?