The name Rion is believed to have originated from the Irish Gaelic language, with roots dating back to the medieval period. It is thought to be a derivative of the Gaelic word "rí," which means "king" or "sovereign." This suggests that the name may have been associated with royalty or nobility in its early days.

In ancient Irish mythology and folklore, there are several references to characters bearing names similar to Rion, such as Rióghán, which means "little king." However, it is uncertain whether these names are direct predecessors or merely share a common linguistic root.

One of the earliest recorded instances of the name Rion can be found in the Annals of the Four Masters, a chronicle of medieval Irish history compiled in the 17th century. The annals mention a figure named Rion mac Fearghail, who was a chieftain of the Uí Fhiachrach Aidne, a prominent Irish clan in the 10th century.

Throughout history, there have been several notable individuals who bore the name Rion. One such figure was Rion Breasail (c. 1580-1646), an Irish poet and historian who lived during the Elizabethan and Jacobean eras. His works, which were written primarily in the Irish language, provide valuable insights into the cultural and political landscape of 16th and 17th-century Ireland.

Another prominent figure was Rion Ó Ceallaigh (1657-1738), an Irish Franciscan friar and scholar. He was a prolific writer and translator, contributing significantly to the preservation and promotion of Irish language and literature during a time of cultural suppression.

In the realm of literature, Rion Ultan (1875-1949) was an Irish novelist and short story writer. He was known for his works that explored the lives and experiences of the Irish rural working class, offering a unique perspective on the social and cultural dynamics of his time.

Moving to the 20th century, Rion O'Conor (1923-1988) was an Irish-American painter and printmaker. He was a prominent figure in the Abstract Expressionist movement and is celebrated for his innovative approach to color and composition.

Lastly, Rion Ó Murchú (1933-2016) was an Irish language scholar and lexicographer. He played a crucial role in the development of modern Irish language dictionaries and contributed significantly to the preservation and promotion of the Irish language throughout his career.