Spring-heeled Jack is an entity in English folklore of the Victorian era. The first claimed sighting of Spring-heeled Jack was in 1837. Later sightings were reported all over the United Kingdom and were especially prevalent in suburban London, the Midlands and Scotland.

There are many theories about the nature and identity of Spring-heeled Jack. This urban legend was very popular in its time, due to the tales of his bizarre appearance and ability to make extraordinary leaps, to the point that he became the topic of several works of fiction.

Spring-heeled Jack was described by people who claimed to have seen him as having a terrifying and frightful appearance, with diabolical physiognomy, clawed hands, and eyes that "resembled red balls of fire". One report claimed that, beneath a black cloak, he wore a helmet and a tight-fitting white garment like an oilskin. Many stories also mention a "Devil-like" aspect. Others said he was tall and thin, with the appearance of a gentleman. Several reports mention that he could breathe out blue and white flames and that he wore sharp metallic claws at his fingertips. At least two people claimed that he was able to speak comprehensible English.