The Ship-Clans were a group that featured in early Romulan civilization after the discovery and Settlement of the Two Worlds.

The members of the Ship-Clans consisted of those travelers that decided to remain on the great starships that had taken them across space to their new homeworlds. This group were reluctant to abandon the large vessels which gave them a great deal of power as they were the only form of space travel available to the Romulans at the time and allowed for constant contact between ch'Rihan and ch'Havran.

The Ruling Queen, T'Rehu, had the support of the Ship-Clans whose vessels allowed her to move her armies allowing her to conquer much of the planet. Later on, rival armies gained the Ship-Clans support through the use of crystals that allowed the creation of laser technology. However, ultimately, the time of the Ship-Clans came to an end when their vessels were too old to support and many of the ship systems were transfered to the developing colonies on the two worlds. This, combined with many departing Ship-Clan members, resulted in their end when the four ships made controlled crashes onto the new homeworld of the Romulan people. (TOS - Rihannsu novel: The Romulan Way)