400 series

400 series may refer to:

Consumer graphics cards

 * Radeon RX 400 series
 * GeForce 400 series

Japanese train types

 * 400 Series Shinkansen
 * GV-E400 series, a DEMU train operated by JR East
 * Osaka Metro 400 series, operated by Osaka Metro since 2023

Other

 * 400-series highways, a network of freeways in Southern Ontario, Canada
 * Rover 400 Series, a small British family car
 * GE-400 series, computers produced by General Electric in the 1960s
 * Kodak DCS 400 series, a series of digital SLR cameras produced by Eastman Kodak
 * Toshiba Satellite Pro 400 series, a series of laptops by Toshiba