Tolkien’s fictional high-elven language is called Quenya.
Quenya is one of the major Elvish languages in Tolkien’s mythology. He modeled aspects of its sound and structure on languages including Finnish, and he developed vocabulary and grammar far beyond the needs of a few isolated words in a novel.
In the histories of Middle-earth, Quenya was associated especially with the High Elves and with the ancient realms of the West. Sindarin, another major Elvish language, became more widely spoken among many Elves in Middle-earth during the later ages.
The two names are often confused because both are Elvish languages created by Tolkien. Quenya is not a general label for every Elvish speech in his legendarium; it specifically identifies one language, while Sindarin identifies another.