James Malcolm Rymer (1814-1884) was a British writer of penny dreadfuls, a cheap form of literature popular in the nineteenth century. Born in London, he is best known for his collaborations with Thomas Peckett Prest, coauthoring Varney the Vampire (1847) and The String of Pearls (1847), a novel also known as Sweeney Todd: The Barber of Fleet Street. Of Scottish descent, Rymer wrote over one hundred novels throughout his career for London publisher Edward Lloyd.