Athea was an isolated and under developed area until the 1830s when the road from Glin to Abbeyfeale was built. As the village of Athea grew, so did its prominence.
According to Samuel Lewis, Athea was part of the civil parish of Rathronan, which also contains some of the parish of Ardagh on the eastern side of the division. During the penal times, the Catholic parish took the name of Athea and dropped the medieval name Rathronan.
Rathronan gets its name from Ráth Ronáin, which means "the Rath of Ronan". Athea was sometimes referred to as Templeathea. Athea is translated into Irish as Áth an tSléibhe which means "the fort of the High Moorland" or "the fort of the Mountain".