||This article describes a work or element of fiction in a primarily in-universe style. (August 2011)
Ciryon is a fictional character in J. R. R. Tolkien's Middle-earth lengendarium. He is referenced in the Appendices of Return of the King, the third and final volume of The Lord of the Rings.
He was Isildur's third son. In the War of the Last Alliance he was sent with his older brother Aratan to garrison the city of Minas Ithil and the pass of Cirith Ungol on the borders of Mordor and Ithilien, in case Sauron tried to escape through the pass. He died in the year 2 of the Third Age at the Battle of the Gladden Fields, along with the rest of the bodyguard of his father Isildur, including his two elder brothers.