Urchin or urcheon is the old English term for hedgehog. As such, it is applied to many things that take a similar form to a hedgehog:
- Sea urchins are spiny sea creatures that are round and prickly like hedgehogs.
- In old theater, urchin was a common name for an elf or fairy that took on a prickly appearance.
- The word "urcheon" is used to refer to the hedgehog in heraldry
It may also refer to:
- Street Urchin, a term for homeless children who live on the street
- Urchin, a 2007 film about a homeless boy living in underground tunnels, written and directed by John Harlacher
- HMS Urchin, the name of four ships of the Royal Navy
- Urchin Software Corporation, a US web analytics company owned by Google
- Urchin (band), a band led by Dave Murray and Adrian Smith of Iron Maiden
- Urchin (detonator), code name for the neutron generating device that triggered the nuclear detonation of the earliest plutonium atomic bombs
- Urchin (zine), a zine published by the Octapod, a media and arts organisation in Newcastle, New South Wales
- Urchin, the squirrel protagonist in the The Mistmantle Chronicles book series.
- Sound of Urchin, an eclectic alternative rock band