The Tagrans were a humanoid civilization from the Alpha or Beta Quadrant of the galaxy, native to the planet Tagra IV.
Tagrans were among the many races and cultures visiting Dayos IV in 2293. (TLE novel: Excelsior: Forged in Fire)
In 2369, they asked for assistance from the United Federation of Planets to help repair the ecological damage to their homeworld caused by pollution. (TNG episode: "True Q")