SC-20 may refer to:

• SC-20, a DEC PDP-10-compatible computer developed by Systems Concepts
• {{USS|SC-20}}, a United States Navy submarine chaser commissioned in 1917 and transferred to the United States Department of War in 1920

• List of minor planets/56901–57000
• List of minor planets/57001–57100
• List of minor planets/5701–5800
• List of minor planets/57101–57200
• List of minor planets/57201–57300
• List of minor planets/57301–57400
• List of minor planets/57401–57500
• List of minor planets/57501–57600
• List of minor planets/57601–57700
• List of minor planets/57701–57800
• List of minor planets/57801–57900
• List of minor planets/57901–58000
• List of minor planets/58001–58100
• List of minor planets/5801–5900
• List of minor planets/58101–58200
• List of minor planets/58201–58300
• List of minor planets/58301–58400
• List of minor planets/58401–58500
• List of minor planets/58501–58600
• List of minor planets/58601–58700
• List of minor planets/58701–58800
• List of minor planets/58801–58900
• List of minor planets/58901–59000
• List of minor planets/59001–59100
• List of minor planets/5901–6000