Altair IV was the fourth planet of the Altair system.
Darien Wallace was born on this planet. (TNG: "Eye of the Beholder")
In 2371, a resident of this world, one Doctor Henri Roget of the Central Hospital of Altair IV, was awarded the prestigious Carrington Award for his work in the field of medicine. (DS9: "Prophet Motive")
Altair IV was also the name of alien world featured in the film Forbidden Planet.
In the novel Beneath the Raptor's Wing, an Earth colony had been settled on Altair IV, and narrowly avoided destruction by Romulan weapons.