The fictional script used to write many Elvish languages in Tolkien’s works is Tengwar.
Tengwar is a writing system devised by the Elf Fëanor in Tolkien’s mythology. Its characters are called tengwa, and its structure can represent different languages through variations known as modes. This flexibility allowed the same script to be adapted for languages such as Quenya and Sindarin.
The script appears in Tolkien’s illustrations and in inscriptions connected with Middle-earth. The Ring-inscription, written in the Black Speech of Mordor, uses Tengwar letters even though the language itself is not Elvish. This is a common source of confusion between a writing system and a language.
Cirth is another Tolkien script, associated particularly with runic forms and the Dwarves. Sarati is an earlier writing system in Tolkien’s invented history, while Angerthas refers to expanded runic arrangements rather than the standard Tengwar system.