Fiver may be:

• A common slang term for:
  • An Australian five-dollar note
  • A British five-pound note
  • A five-euro note
  • A United States five-dollar bill
  • A [Half a Sawbuck...]
  • When a cricket bowler gets 5 wickets in a single inning.
• A fifth columnist or saboteur, in wartime slang
• A large forehead, generally the height of five fingers placed horizontally on the forehead.
• Fiver (racing), a Swedish endurance racing team
• 5*, a UK TV channel operated by Channel 5 formerly known as Fiver
• Fiver (puzzle), a math game played on a 5x5 grid, distantly related to Conway's Game of Life
• Fiver (Watership Down), a fictional rabbit in the Richard Adams novel Watership Down
• FIVER, a product, marketing and sales firm focused on the Youth Culture consumer
• The Fiver, a humorous daily football email by The Guardian newspaper
• Fiverr, a global online marketplace for buying and selling services starting at $5
• Zaidiyyah Shi'a Muslims, who disagree with the majority of Shi'a on the identity of the Fifth Imam

5* (pronounced "five star") is a television channel in the United Kingdom owned by Viacom International Media Networks Europe. It is a sister channel of Channel 5 and 5USA. The channel was launched as "Five Life" on 15 October 2006, and was rebranded as "Fiver" on 28 April 2008, and "5*" on 7 March 2011. The channel is available on digital television via Freesat, Freeview, Sky, and Virgin Media. 5* broadcasts between 09:00 and 00:00. It was originally launched by RTL Group (the former owner) as part of their multi-channel strategy, which all other analogue broadcasters, such as ITV plc and Channel 4, had already achieved.