Hop-o'-My-Thumb (Hop-on-My-Thumb), or Hop o' My Thumb, also known as Little Thumbling, Little Thumb, or Little Poucet, is one of the eight fairytales published by Charles Perrault in Histoires ou Contes du temps passé (1697), now world-renowned. It is Aarne-Thompson type 327B. The small boy defeats the ogre. This type of fairytale, in the French oral tradition, is often combined with motifs from the type 327A, similar to Hansel and Gretel; one such tale is The Lost Children.

Histoires ou contes du temps passé, avec des moralités or Contes de ma mère l'Oye is a collection of literary fairy tales written by Charles Perrault, published in Paris in 1697. The work became popular because it was written at a time when fairy tales were fashionable amongst aristocrats in Parisian literary salons. Perrault wrote the work when he retired from court as secretary to Jean-Baptiste Colbert, minister to Louis XIV of France. Colbert's death may have forced Perrault's retirement, at which point he turned to writing. Scholars have debated as to the origin of his tales and whether they are original literary fairy tales modified from commonly known stories, or based on stories written by earlier medieval writers such as Boccaccio.