K'Tyll was a Vulcan who served as an agent of the El-Keshtanktil during the 23rd century.
In 2259, K'Tyll accompanied T'Pring to Starbase 1 at the latter's request, as T'Pring had hoped to spend the majority of her time there with her fiancé Spock. Their mission was to apprehend the V'tosh ka'tur criminal Barjan T'Or. However, Barjan insisted on surrendering only to T'Pring, forcing K'Tyll to summon her colleague. (SNW: "Spock Amok")
K'Tyll was played by Tahirih Vejdani.