Castor was an American indie rock/emo band from Champaign-Urbana, Illinois. Formed in 1994, they were known for their "fluid" sound, often changing time signatures several times in a song while maintaining the flow of the music. They released two albums, the first self titled in 1995, the second Tracking Sounds Alone posthumously in 1998. Both albums are now out of print and only available in digital format online.

Singer and guitarist Jeff Garber and bassist Derek Niedringhaus recorded an album under the band name "Big Bright Lights" in 1997 which was not released until 2001.