Streamline may refer to:
- Streamlines, streaklines, and pathlines, in fluid flows
- Streamline Airlines
- Streamliner, any vehicle shaped to be less resistant to air
- Streamline (swimming), the position a swimmer takes underwater after pushing off a pool wall
- Adobe Streamline, a discontinued line tracing program made by Adobe Systems
- Streamline Cars Ltd, the company responsible for making the Burney car
- Streamline Distributed Debugging Tool, a debugger produced by Allinea primarily for debugging parallel programs
- Streamline Moderne, an architectural style related to Art Deco
- Streamline Pictures, an American distribution company best known for distributing English dubbed Japanese animation
- Streamline Studios, an independent Dutch outsourcing and game developing studio
- Hal Roach's Streamliners, a series of short films made in the 1940s
- Streamline (comics), a fictional super-hero character