400R can refer to:
Allison World 400R, a transmission built for transit buses by Allison Transmission Goodyear GA-400R Gizmo, a helicopter developed by Goodyear Honda XR 400R, an off-road motorcycle produced by Honda Kawasaki Ninja 400R, a 2011 sport bike manufactured by Kawasaki Nismo 400R, a special edition variation of the Nissan Skyline R33 Privia PX-400R, a digital piano manufactured by Casio