Cosmic dust is dust which exists in space. Most cosmic dust particles are between a few molecules to 0.1 µm in size. A smaller fraction of all dust in space consists of larger refractory minerals that condensed as matter left the stars. It is called "stardust" and is included in a separate section below. The dust density in the local interstellar medium of the Local Bubble is approximately 10⁻⁶ × dust grain/m³ with each grain having a mass of approximately 10⁻¹⁷ kg.

Cosmic dust can be further distinguished by its astronomical location: intergalactic dust, interstellar dust, interplanetary dust (such as in the zodiacal cloud) and circumplanetary dust (such as in a planetary ring). In the Solar System, interplanetary dust causes the zodiacal light. Sources of Solar System dust include comet dust, asteroidal dust, dust from the Kuiper belt, and interstellar dust passing through the Solar System. The terminology has no specific application for describing materials found on the planet Earth except for dust that has demonstrably fallen to Earth. By one estimate, as much as 40,000 tons of cosmic dust reaches the Earth's surface every year. In October 2011, scientists reported that cosmic dust contains complex organic matter ("amorphous organic solids with a mixed aromatic–aliphatic structure") that could be created naturally, and rapidly, by stars.

Cosmic Dust, also known as the Cosmic Dust Fusion Band, is an instrumental jazz band formed in 1990 by Jim Templeton. The band was the first well-known group that guitarist Myles Kennedy played in. The original lineup consisted of Jim Templeton on keyboard, Gary Edighoffer on saxophone, Clipper Anderson on double bass, Myles Kennedy on guitar, and Scott Reusser on drums. Kennedy eventually left the band and went on to become the lead vocalist/lead guitarist for a jazz fusion group called Citizen Swing and later an alternative rock band called The Mayfield Four. Kennedy is now fronting and playing guitar for the hard rock/alternative metal band Alter Bridge, which he helped form with Creed members Mark Tremonti, Scott Phillips, and Brian Marshall in 2004, and is also the lead vocalist for Slash's solo band on tour.

Cosmic Dust has released two albums, Journey in 1991 and Step Right Up! in 2008. Both albums are carried by Peterson Entertainment, Llc (www.petersonentertainment.com)