First World War has broken out in Europe. Meanwhile, sailor Charlie Allnut (Humphrey Bogart) delivers supplies to the villages in Eastern Africa with his river steamboat ‘African Queen’. When reverend Samuel is murdered, Allnut offers to take his sister Rose (Katharine Hepburn) in his boat. It will be a dangerous and trouble-packed journey. The distance between the main characters, created by their clashing personalities will not help them.