The fictional language Tolkien created for the elves of Valinor is Quenya.
Quenya is one of the major Elvish languages in Tolkien’s legendarium. He based much of its sound and structure on Finnish, while also drawing inspiration from Latin and Greek. In the stories, it was associated especially with the High Elves, including the Noldor, who brought it from Valinor to Middle-earth.
Quenya was not simply a collection of invented words. Tolkien developed its grammar, pronunciation, vocabulary, and historical changes over many years. He treated language creation as a central part of world-building, often imagining peoples and histories from the languages outward.
Sindarin is the other best-known Elvish language, but it developed in Middle-earth and became more widely spoken there. Quenya remained prestigious and ceremonial, much like a learned or classical language. Famous Quenya words include “Eärendil,” “Valinor,” and “Nai.”