Streamline may refer to:

• Streamline Air, American regional airline
• Adobe Streamline, a discontinued line tracing program made by Adobe Systems
• Streamline Cars, the company responsible for making the Burney car

• Streamlines, streaklines, and pathlines, in fluid flows
• Streamliner, a vehicle shaped to be less resistant to air

• 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
• Stream Line, the English title of the 1976 Italian film La linea del fiume starring Philippe Leroy
• Streamline, a newsletter published by the Migrant Clinicians Network

• Streamline Ewing (1917–2002), American jazz trombonist
• Streamline (Lenny White album), 1978
• Streamline (Lee Greenwood album), 1985
• "Streamline" (song), a 1994 song by Newton
• "Streamline", a song by System of a Down from the 2002 album Steal This Album!
• "Streamline", a song by Pendulum from the 2005 album Hold Your Colour
• "Streamline", a song by From Autumn to Ashes from the 2005 album Abandon Your Friends
• "Streamline", a song by VNV Nation from the 2011 album Automatic

• Streamline (film), an Australian film directed by Tyson Wade Johnston
• Orel VH2 Streamline, a French aircraft design
• Streamline (swimming), the position a swimmer takes underwater after pushing off a pool wall
• Streamline Moderne, an architectural style related to Art Deco
• Operation Streamline, a program in the United States to prosecute illegal immigrants
• Streamline, a brand of the United States Playing Card Company

• Drag (physics)
• Optimization (computer science)
• Process optimization
• Rightsizing
• Streamlining the cities