A Romulan cruiser was a general term referring to Romulan starships.

In 2365, Donald Varley recorded a personal log aboard the USS Yamato stating that they had "been spotted by a Romulan cruiser, but after playing hide and seek through several solar systems" he thought they had lost them. (TNG: "Contagion")

In a holoprogram created by Barash, William T. Riker had, in 2382, saved a Romulan cruiser with failed warp coils that had drifted into Federation space. This action impressed the Romulans and was the first step toward an alliance. (TNG: "Future Imperfect")