Superbird-B2, also known by its pre-launch designation Superbird-4, is a Japanese communications satellite which is operated by SKY Perfect JSAT Group.

[3] It was constructed by Hughes Space and Communications and is based on the HS-601 HP satellite bus.

[2] It was built at the Los Angeles plant, California, United States.

Following its launch and on-orbit testing, it was placed in geostationary orbit at 162° East, from where it provides communications services to Japan.

Currently, the J-Alert (Japanese emergency warning system) is broadcast via Superbird-B2.