The name Trahern is of Irish origin and is a variant spelling of the name O'Tiarnaigh, which was once one of the most powerful families in County Mayo, Ireland. The name comes from the Old Irish word "tighernach," which means "poet" or "storyteller." The O'Tiarnaigh family were known as great poets and scholars, and they were descended from Tigernach Ua Maile Dhuibh, a 10th-century chieftain who was also a renowned poet. Over time, the name O'Tiarnaigh became anglicized to Trahern, and it has been used as a given name in Ireland and among Irish communities around the world ever since.
The name Trahern has seen a modest presence in the United States over the past few decades. In 1969, there were five newborns given the name Trahern. This number increased slightly by one in 1986, with six babies being named Trahern that year. Overall, from these two years combined, there have been a total of eleven births with the name Trahern in the United States.