Y'jarvians are an Iraxian-based humanoid sentient race that evolved on the planet of Jarvic. Y'jarvians are omnivorous, and unlike most Iraxian-based sentient races, they cannot see in normal light. Instead, they can see in ultraviolet light through sensory organs on the top of their heads.

The Y'jarvians have long been a major power in the Galaxy through the Yjarvian Empire and later, the Yjarvian Republic. Although their military is not as large as that of the Vystok Empire, they are still a formidable force. Such a military first saw widespread action in the First War.