The name Orrin has its origins in the Gaelic language, which was spoken by the Celtic people of Ireland, Scotland, and the Isle of Man. It is believed to have derived from the Gaelic word "orran," which means "green" or "fresh." The name's roots can be traced back to the Middle Ages, around the 5th to 15th centuries.

One of the earliest recorded instances of the name Orrin can be found in the Annals of Ulster, a chronicle of medieval Irish history. The Annals mention an Orrin who lived in the 7th century and was a prominent figure in the Kingdom of Dál Riata, which spanned parts of modern-day Scotland and Northern Ireland.

In the 12th century, an Orrin ap Iorwerth was a notable Welsh prince and military leader who fought against the Norman invaders. He played a significant role in the struggle for Welsh independence during the Norman conquest of Wales.

During the Scottish Wars of Independence in the late 13th and early 14th centuries, an Orrin of Argyll was a Scottish nobleman and warrior who fought alongside William Wallace and Robert the Bruce against the English forces.

In the 16th century, Orrin Ostrander was a Dutch settler in the New Netherland colony, which later became part of New York. He was among the earliest European settlers in the region and helped establish the Dutch presence in North America.

Another notable figure with the name Orrin was Orrin Porter Rockwell, an American frontiersman, lawman, and bodyguard of Joseph Smith, the founder of the Latter Day Saint movement. Rockwell lived from 1813 to 1878 and played a significant role in the early history of the Latter Day Saint movement in the United States.