Cirrus may refer to:

In science:

  • Cirrus cloud, a type of cloud
  • Cirrus (rocket), a German research rocket
  • Cirrus, a fleshy, downward extension of the upper lip in salamanders or fish
  • Cirrus, a thoracic limb of an adult barnacle
  • Cirrus (plural cirri), an unbranched appendage found in many invertebrate groups such as the Polychaeta and Echinodermata
  • Cirrus (plural cirri), a tuft of fused cilia found in certain protozoa and used in locomotion

In the aviation industry:

  • ADC Cirrus, a series of British aircraft engines in the 1920s
  • Blackburn Cirrus Major, a British four-cylinder aircraft engine first run in 1936
  • Blackburn Cirrus Minor, a British four-cylinder aircraft engine first run in 1937
  • Cirrus Aero-Engines, a defunct British aircraft engine company
  • Cirrus Aircraft, an aircraft manufacturer in Duluth, Minnesota
  • Cirrus Airlines, a German airline in Saarbr├╝cken, Germany
  • Schempp-Hirth Cirrus, an Open-class sailplane
  • Schempp-Hirth Standard Cirrus, a Standard-class sailplane

In other industries:

  • Chrysler Cirrus, a car produced by DaimlerChrysler between 1995 and 2000
  • Cirrus (interbank network), an interbank network by MasterCard
  • Cirrus Logic, a semiconductor manufacturer
  • Microsoft Jet Database Engine or Cirrus

In other uses:

  • Cirrus (band), a duo of electronic music composers
  • Cirrus (building), a high-rise apartment building in Helsinki, Finland
  • Cirrus Vodka, a vodka made in Virginia, USA