Alpha Majoris is a star, the primary of the Alpha Majoris system. The system included the planet Alpha Majoris I. (TOS: "Wolf in the Fold") The location of Alpha Majoris was depicted on a Federation star chart. It was located near Omega Cygni. (TNG: "Conspiracy")

The first planet of the system was home to an animal known as the Mellitus, a "cloud creature". In its normal state, it existed as a gas held together by a highly cohesive electromagnetic field. When the mellitus stopped, it became solid. These abilities were considered similar to those possessed by the Redjac entity. (TOS: "Wolf in the Fold")