AR Cephei (AR Cep) is a variable star in the constellation Cepheus. It is classified as a semiregular star with a spectral type of M4III.
Aernout de Sitter discovered the star in 1933. It was given its variable star designation, AR Cephei, in 1939.
AR Cephei is located approximately 1,010 light-years (309 parsecs) from the Solar System, and has a radial velocity of -16 km/s, meaning that it is moving toward the Sun at ~16 kilometers every second.