The name Erin is derived from the Irish Gaelic word "Éirinn", which means "an abundant land" or "green land". It is the name of the island of Ireland and has been used as a given name for both males and females.

Erin has been a popular name in Ireland for centuries, and it is believed to have its roots in ancient Celtic mythology. The name is closely associated with the Irish goddess of sovereignty, Ériu, who was said to have been one of the wives of the mythical king Éber.

The earliest recorded use of the name Erin dates back to the 16th century, when it was used as a poetic name for Ireland. It became more widely used as a personal name in the 18th and 19th centuries, particularly among Irish families living in the United States and other English-speaking countries.

One of the earliest notable individuals with the name Erin was Erin the Messenger, a 6th-century Irish monk and scribe who is believed to have been one of the first to bring Christianity to Scotland. Another early figure was Erin of Clonmacnoise, a 9th-century Irish princess and abbess who founded a monastery in County Offaly, Ireland.

In more recent history, notable individuals named Erin include Erin Brockovich (born 1960), an American legal clerk and environmental activist whose fight against Pacific Gas and Electric Company was the subject of a 2000 film starring Julia Roberts. Erin Moran (1960-2017) was an American actress best known for her role as Joanie Cunningham on the sitcom "Happy Days".

Other famous Erins include Erin Andrews (born 1978), an American sportscaster and television personality, and Erin Hunter (born 1963), the pen name of several authors who write the popular children's book series "Warriors".

In the literary world, one of the most notable Erins is Erin Morgenstern (born 1978), the American author of the bestselling novel "The Night Circus".