Placidus II was a planet located somewhere in the space of the galaxy's Alpha or Beta Quadrants, the second planet in orbit of the Placidus star system. By the 2370s, Placidus II was a holding of the Romulan Star Empire, and was considered a friendly port of call by the Romulan Imperial Fleet. (ST video game: Starfleet Command III)

In gameplay, this name was part of a list that were applied to planets on the game map, with random attributes assigned to them.