Who was the father of Lúthien?

The father of Lúthien was Thingol, the Elven king of Doriath. He was also known as Elu Thingol, so both names refer to the same character in Tolkien’s mythology.

Thingol was a Sindarin Elf and ruled the hidden forest kingdom of Doriath during the First Age. His wife was Melian, a Maia, making Lúthien the child of an Elven king and a supernatural being of divine order. Lúthien was their only child and became one of the central figures of The Silmarillion.

When the mortal man Beren sought to marry Lúthien, Thingol demanded an apparently impossible bride-price: one of the Silmarils taken from Morgoth’s Iron Crown. The quest led to one of Tolkien’s most important legends, the love story of Beren and Lúthien.

A common mix-up is that “Elwë” was Thingol’s original name. In Quenya he was called Elwë Singollo, while “Thingol” is the Sindarin form meaning “Greycloak.” Thus the stored answer is the familiar canonical name, not a different character. Lúthien’s descendants include Elrond, Arwen, and Aragorn.