In fluid dynamics, a streamline is a line which is everywhere tangent to the velocity of flow. It can also have other meanings:

• A style of industrial design, popular in the 1930s, applying streamlines to the shape of products.
  • A streamliner is a vehicle, usually a locomotive, that incorporates streamlining to produce a shape that provides less resistance to air.
  • Streamline Moderne, an architectural style, was a late branch of the Art Deco style.
• Streamlining, a business term often synonymous to downsizing.
  • Streamlining the cities, a paper with proposals for reorganising local government in Greater London.
• Streamline Cars Ltd, the company producing the Burney car.
• Streamline Pictures, an American film company.
• Adobe Streamline, the name of a discontinued line tracing program made by Adobe Systems.
• Streamline Distributed Debugging Tool, a debugger produced by Allinea Software Ltd.
• Streamline, a song by the band Newton, used in a Pepsi Cola commercial.