ATW could refer to:

• the airport at Appleton, Wisconsin, United States (IATA airport code ATW)
• Arriva Trains Wales railway service in the United Kingdom
• Atari Transputer Workstation computer
• Atlantic and Western Railway (AAR reporting mark ATW)

ATW is also the name of a German automobile, an electric minicar produced since 1983. The car features a monocoque body supplied by a French builder of boats.