Decoder may refer to:

• Audio decoder converts digital audio to analog form
• Binary decoder, digital circuits such as 1-of-N and seven-segment decoders
• Decompress (compression decoder), converts compressed data (e.g., audio/video/images) to an uncompressed form
• Instruction decoder, an electronic circuit that converts computer instructions into CPU control signals
• Quadrature decoder, converts signals from an incremental encoder into counter control signals
• Video decoder, converts base-band analog video to digital form

• Decoder (band), a defunct post-hardcore band that was briefly named Lead Hands
• Decoder (duo), a drum and bass duo
• Decoder (album)

• Decoder (film), a 1984 West German film

• Decoding methods
• Code (disambiguation)
• Recode (disambiguation)