Now known as a beach resort, in past times Fethard was a place of some importance. It was the site of Norman landings in the 12th Century,and the remains of Norman-era earthworks and fortifications may be seen at Baginbun Bay, south of Ingard Point.
A 12th Century castle was built by Raymond de Gros, which passed to the Bishop of Ferns and was used as an episcopal residence. There is little evidence of the castle today. Alexander Devereux (the 16th century bishop of Ferns and Abbot of Dunbrody) is buried in what is now the protestant church.
Fethard was granted a charter by James I, and became municipal borough, sending 2 members to the Irish parliament, before its dissolution. In 1798 a harbour was built and was a landing site for French troops during the revolutionary wars.
In modern times the main industry has been fishing.
The village has a population of 253: It lies in the electoral district of Fethard in the constituency of County Wexford. It is bordered by the districts of Bannow and Ballyhack.
A parish in the Roman catholic diocese of Ferns, Fethard is bordered by the parishes of Templetown and Poulfur.
Fethard-on-Sea is often associated with the Fethard-on-Sea Boycott.